Lasagne, ragout and more great dishes from top cooks including Nigel Slater and David Tanis, chosen by Observer Food Monthly The final part of this series launches tomorrow at 8am

Bruno Loubets cocotte of spring and summer vegetables

My father used to love his garden; it was his pride and joy. In spring and summer, he often used to bring home a large basket with a colourful selection of young vegetables. The look on his face and his body language sent a clear message; here was a man that was excited, proud and happy with the fruits of his labour. He always handed the basket to my mother like a beautiful bouquet of flowers. A couple of hours later, the little gems would end up in the middle of the kitchen table in a large Le Creuset cocotte, exuding the most lovely scent and confirming their organic credentials.

Serves 6
olive oil 4 tbsp
baby carrots 12
baby fennel bulbs 6, trimmed and peeled
radishes 18 small, trimmed
salt and black pepper
garlic 1 clove
summer savoury 1 tbsp
baby leeks 6, trimmed
runner beans 4, topped, tailed and cut into pieces
baby courgettes 6
podded fresh broad beans or frozen broad beans 150g
peas 150g
cherry tomatoes 12
asparagus spears 6
double cream 2 tbsp
butter a knob
thyme leaves tsp
flat-leaf parsley 1 tbsp, chopped
chives 2 tbsp, chopped
chervil 1 tbsp, chopped
basil 2 tbsp
lemon , to finish

Heat the olive oil in a large pot, such as a cocotte, over a medium heat.

Add the carrots, fennel and radishes. Season with salt and pepper then add the garlic and summer savoury. Stir well, cover with a lid and lower the heat as far as it will go. Cook for about 5 minutes or until the carrots are al dente, then remove the lid and add the baby leeks and runner beans. Stir well then add half a glass of water. Replace the lid, keeping it slightly ajar at one side. Leave to cook for 3 minutes, then add the remaining vegetables.

Mix well, then add another half-glass of water and replace the lid, again slightly ajar, and cook for a further 3 minutes. Remove the lid, then add the cream, butter and the herbs, swirl the pan to mix everything together (using a spoon to mix it might break up or damage the delicate vegetables), then squeeze over a little lemon juice. Swirl again then serve the pot in the middle of the table.

From Mange Tout by Bruno Loubet (Ebury Press, 25). Click here to buy a copy from Guardian Bookshop for 20

David Taniss wild mushroom ragout with ziti

Photograph: Tessa Traeger for the Observer

Although many vegetarians I know are understandably tired of pasta, this deeply satisfying dish isnt so much a pasta as a rich mushroom stew that would be just as wonderful with warm polenta, steamed rice, or other grains.

Serves 4-6
olive oil 65ml
onion 1 large, finely diced
salt and pepper
wild or cultivated mushrooms 900g, cleaned and sliced
garlic 3 cloves, smashed to a paste with a little salt
thyme 1 tsp, finely chopped
sage 2 tsp, finely chopped
red pepper flakes tsp
tomato paste 2 tbsp
plain flour 1 tbsp
porcini mushroom broth 500ml, hot, or as needed (see directions below)

For the ziti
long ziti 450g (f you cant find ziti any tubular pasta will do)
olive oil or butter 2 tbsp
garlic 2 cloves
salt and pepper
parsley 2 tbsp, chopped

To make the porcini mushroom broth, put 770ml water in a saucepan and add a bay leaf, a few slices of dried porcini mushrooms or 2 tsp dry porcini powder, half a small onion, 1 small celery stalk and a small carrot, peeled and chopped. Bring to a boil, then lower to a simmer and cook for 20-30 minutes; strain.

To prepare the ragout, in a large frying pan, heat 2 tablespoons of the olive oil over high heat. Add the onion and cook, stirring well, until it begins to brown. Lower the heat to medium, season the onions with salt and pepper, and continue stirring until nicely caramelised, about 5 minutes. Remove the onion to a small bowl. Return the pan to the heat, add the remaining 2 tablespoons olive oil, and turn the heat to high. Add the mushrooms, stirring well to coat with oil. Keep the heat high and saut the mushrooms until they brown lightly. If juices accumulate in the pan, pour them off and reserve.

Season the mushrooms with salt and pepper, add the garlic, thyme, sage and pepper flakes, and stir well. Reduce the heat to medium, add the caramelised onion and the tomato paste, and stir well to coat the mushrooms and to dry the mixture slightly. Cook for another 2 minutes, stirring.

Sprinkle the flour over the mixture and stir it in. Ladle in 1 cup of the hot mushroom broth, stirring well as the mixture thickens. Add another cup of hot broth and let the ragout cook for another 5 minutes. If its too thin, cook it a bit longer; if too thick, add a bit more broth. Taste for seasoning. (The ragout can be made a few hours ahead and reheated.)

To make the ziti, bring a large pot of salted water to a boil. Break the ziti into 15cm lengths (or use cut ziti). Boil the pasta for about 10 minutes, or until on the firm side of al dente.

When the noodles are almost cooked, warm the olive oil or butter in a large wide frying pan. Put in the garlic and stir; dont let it brown. Add salt and pepper and turn off the heat. Drain the pasta, add to the frying pan along with the parsley, and mix well. Transfer the pasta to a warm serving bowl. Put the hot mushroom ragout in another serving bowl, and bring them both to the table.

From Heart of the Artichoke by David Tanis (Artisan, 25)

Nigel Slaters stuffed peppers

Photograph: Jonathan Lovekin

Rice has for centuries been the obvious contender for stuffing a pepper and indeed aubergines or a beefsteak tomato flavoured with caramelised onions, golden sultanas and musky raisins and seasoned with capers, anchovies, cinnamon and cumin. Small grains cracked wheat, brown rice, quinoa are eminently suitable fillings, as is any type of small bean, lentil or the plump, pearl-shaped couscous known as mograbiah. Vegetable stuffings can set the pepper alight.

Piercing, cherry-sized tomatoes, such as Sungold and Gardeners Delight, or chunks of sweet steamed pumpkin offer more than just jewel colours to lift the spirits. They have a brightness of flavour very different from the humble, homely grains. They offer a change of step. A few hand-torn chunks of mozzarella and some olive oil will produce a seductive filling. Minced beef, the knee-jerk filling, somehow makes my heart sink.

Mograbiah, sometimes known as pearl couscous, takes the idea on a bit, having the comforting, frugal qualities of rice but possessing an extraordinary texture, poised between pasta and couscous. Made of wheat and sometimes known as fregola, it is available from Middle Eastern grocers shops.

Enough for 4
ripe peppers 4 medium to large

For the stuffing
mograbiah (pearl couscous) 200g
olive oil
spring onions 6
garlic 2 cloves, sliced
ground paprika tsp
lemon grated zest and juice of
mint leaves a large handful, chopped
coriander leaves a large handful, chopped
pine nuts 75g, toasted

For the yogurt sauce
thick yogurt 200g
coriander and mint a handful each, chopped
paprika a pinch
black pepper

To make the stuffing, cook the mograbiah in plenty of well-salted boiling water (use the same amount of salt you would to cook pasta) for about 15 minutes, till tender. Drain and toss lightly with a little olive oil to stop the pearls sticking together.

Meanwhile, finely chop the spring onions, discarding only the very darkest of the green shoots, and let them soften over a moderate heat in a glug or two of olive oil. Just before they start to colour, add the garlic, then the paprika and the grated lemon zest. Stir in the chopped herbs and the toasted pine nuts. When all is fragrant and starting to darken a little in colour, stir in the drained mograbiah and the lemon juice. Season carefully.

Set the oven at 180C/gas mark 4. Cut the peppers in half, tug out the seeds and cores and lay the halves cut-side up in a baking tin. Pile the filling into the peppers, drizzle over a little more olive oil and cover loosely with foil. Bake for about 45 minutes, until sizzling.

To make the sauce, mix the yogurt with the herbs, paprika and a grinding of black pepper. Spoon it over the peppers at the table.

From Tender Volume 1 by Nigel Slater (Fourth Estate, 30). Click here to buy a copy from Guardian Bookshop for 20

Dan Barbers carrot romesco with polenta

Photograph: Tessa Traeger for the Observer

Serves 4-6
For the carrot romesco
whole almonds 140g, blanched
pine nuts 35g
hazelnuts 35g, blanched
stale bread 55g, crusts removed, cubed
olive oil 85ml, plus 1 tbsp
carrots 3 large, peeled and thinly sliced
fresh carrot juice 240ml
sherry vinegar 2 tbsp
smoked Spanish paprika 1 tsp
Aleppo pepper tsp (or substitute red pepper flakes)
salt and pepper
freshly grated Parmigiano-Reggiano or alternatively shaved hazelnuts to garnish

For the polenta
milk 500ml
water 500ml
salt and freshly ground pepper to taste
polenta 160g (freshly ground if possible)
butter 1 tbsp
mascarpone 1 tbsp, optional

Preheat an oven to 190C/gas mark 5. Combine the nuts on a small baking tray and toast for 10 minutes until golden. Remove and allow to cool.

In a small bowl, toss the cubes of bread with 1 tablespoon of olive oil. Spread on a small baking tray and toast until well browned, about 10-12 minutes. Remove from the oven and cool.

Combine the carrots and carrot juice in a small pot and bring to a simmer. Cover and cook for about 20 minutes at a low simmer until the carrots are completely soft and the liquid has reduced by about half.

Transfer the cooked carrots and juice to a food processor, along with the toasted nuts and bread. Puree with the remaining olive oil, sherry vinegar, paprika and Aleppo pepper. Season well with salt and pepper.

To make the polenta, in a large saucepan over medium-high heat, bring the milk and water to a simmer. Season generously with salt and pepper.

Whisking constantly, slowly add the ground polenta. Reduce the heat to medium-low and cook, whisking frequently, until softened, about 15 minutes. Whisk in the butter and mascarpone and season to taste.

To serve, spoon the creamy polenta into a bowl. Top with carrot romesco and garnish with aged parmesan or alternatively shaved hazelnuts.

Dan Barber is chef and co-owner of Blue Hill, NYC, and Blue Hill at Stone Barns, New York State

Jane Scotter and Harry Astleys summer vegetable lasagne

Photograph: Tessa Traeger for the Observer

This luxurious lasagne takes quite a long time to prepare and uses many in-season summer vegetables. The method for layering it ensures it stays really moist and luscious.

Serves 8
For the tomato sauce
olive oil 5 tbsp
onion 1 large, finely diced
celery 1 stick, finely diced
carrot 1, finely diced
garlic 3 cloves, crushed
thyme 2 tsp, finely chopped
oregano 2 tsp, finely chopped
bay leaves 2
red or white wine 50ml (optional)
ripe plum tomatoes 2kg, cut into quarters, or 4 x 400g cans of tomatoes
tomato puree 1 dsp

For the filling
aubergines 2 (about 700g in total)
courgettes 500g
sea salt 2 tsp
red peppers 4
olive oil 4 tbsp
swiss chard 500g
dried or fresh lasagne sheets 400g
mozzarella 2 balls (a vegetarian mozzarella can be used here)
basil 125g
parmesan 100g, grated (a hard vegetarian cheese can be substituted)
sea salt and black pepper

For the bchamel sauce
milk 1.5 litres
bay leaf 1
onion 1 small , peeled and halved
butter 90g
plain flour 90g
mustard 1 tsp
comt cheese, or similar melting cheese such as gruyre or emmental 150g, grated (a semi-hard vegetarian cheese can be substituted)

For the tomato sauce, heat the olive oil in a heavy-based pan over a moderate heat. Add the onion, celery, carrot and garlic and stir to coat in the oil. Reduce the heat, cover and sweat the vegetables for about 10 minutes, until soft. Stir in all the herbs, cook for 2 minutes, then turn up the heat and pour in the wine, if using. Stir until most of the wine has evaporated. Lower the heat and add the tomatoes. Season to taste. Cover and stew until the tomatoes begin to break down. Stir in the tomato puree and simmer, uncovered, until thick. Depending on how juicy the tomatoes are, this might take up to an hour.

While the sauce is cooking, prepare the vegetables. Heat the oven to 200C/ gas mark 6. Trim the aubergines and courgettes and slice them lengthways into strips about 5mm thick. Lay the aubergine slices out on a roasting tray and sprinkle the sea salt over them. Set aside for at least half an hour, to sweat out any bitter flavours.

Meanwhile, put the peppers on a baking sheet and roast for about 30 minutes, until they are soft and lightly charred. Seal the hot peppers immediately in a plastic bag. When they are cool enough to handle, cut them in half, remove the seeds and the green stem, then peel off the skin. Cut the peeled peppers into long strips and set aside.

Rinse the aubergines and drain, then pat dry. Lay the slices on a clean baking sheet. Do the same with the courgette slices. Spoon over the oil and place in an oven preheated to 220C/gas mark 7. Roast for 20-30 minutes, turning once, until lightly browned on both sides. Shred the chard and steam it very briefly so that it wilts but doesnt cook. Drain well.

Finally, make the bchamel sauce. Pour the milk into a pan, add the bay leaf and onion and bring slowly to boiling point. Remove from the heat and set aside for about half an hour to infuse. Melt the butter in a pan over a low heat, add the flour and cook, stirring, for a minute or two.

Gradually strain in the milk, omitting the bay leaf and onion, then raise the heat and bring to a simmer to make a thick, smooth sauce. Continue to cook over a low heat for 3-4 minutes. Add the mustard and grated cheese and season to taste.

Layer the lasagne as you wish or try our method, which works well, and cooks the pasta so that it remains nice and moist. There are 3 layers of tomato sauce and pasta and 2 of bchamel sauce. Spoon a layer of tomato sauce into a 25cm x 35cm lasagne dish or a deep roasting tin. Add a layer of pasta sheets, followed by another layer of tomato sauce, then a layer of aubergine and courgette. Tear the mozzarella into small pieces and dot them over the aubergine and courgettes. Add another layer of pasta and arrange the peppers on top. Next arrange the chard leaves evenly in the dish and pour half the bchamel over it. Now add another layer of pasta and the final layer of tomato sauce. Spread the basil leaves over the top and then pour the remaining bchamel evenly over, making sure it spreads into the corners. Scatter the grated parmesan over the top and place in the middle shelf of an oven preheated to 200C/gas mark 6.

Bake for about 1 hour, until the sauces are bubbling and the top is lightly browned. Serve with a green salad.

From Fern Verrow by Jane Scotter & Harry Astley (Quadrille, 25). Click here to buy a copy from Guardian Bookshop for 20

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