The mushroom season is upon us and the foragers at Petersham Nurseries have been busy. Here, Skye Gyngell shows what to do with her favourite, the porcini.

There is something wonderful about the almost damp, mossy taste of porcini. Their delicate, flavour is as light as air and they are as good raw as they are cooked.

I always look forward to autumn for its abundance of produce: quince, cobnuts, game, apples, pears, cold-water fish and mussels. It is a truly bounteous time and here at Petersham Nurseries we really try and make the most of it before the bleak winter months set in.

It is also the time for mushrooms: truffles, girolles, trompette de la mort, pied de mouton and porcini. Porcini are my absolute favourite - I love all mushrooms, but there is something wonderful about the almost damp, mossy taste of porcini that I just adore. Porcini grow from summer until autumn, following plentiful rainfall, and are found throughout the UK and Europe. Their deep, delicate flavour is as light as air and they are just as good raw and finely sliced as they are cooked. In fact, in one of these recipes I have not cooked them, choosing to enjoy their subtlety just as nature made them.

Skye Gyngell is head chef at Petersham Nurseries, Church Lane, off Petersham Road, Richmond, Surrey, tel: 020 8605 3627. Her book, 'A Year in My Kitchen', is published by Quadrille, priced £25. To order a copy at the special price of £22, plus free p&p, call Independent Books Direct on 08700 798 897

Wild mushroom and porcini soup

This is a quick and simple autumn soup that is utterly delicious. Beware though - quite a small amount will suffice as the flavour is very rich. Ask your greengrocer for roughly 500g (1lb) of mixed wild mushrooms - they may well include trompette de la mort, pied de mouton, girolle and cep.

Serves 4

500g/1lb of wild mushrooms (including porcini)
1 clove garlic, peeled and finely sliced
A large knob of butter
1tsp Dijon mustard
50ml/2fl oz verjus (or white wine)
50ml/2fl oz crème fraîche
1 small bunch flat leaf parsley, finely sliced
Freshly ground black pepper

Clean the mushrooms well by gently wiping them over with a mushroom brush (if you don't have one, a pastry brush works just as well), being careful to remove all the dirt and grit (and the occasional pine-needle).

Melt the butter in a heavy-based saucepan over a medium heat; when foaming, add the mushrooms and the garlic and cook without stirring for 2 minutes. Add the mustard and verjus or white wine. Allow the wine to bubble and reduce slightly, then add the crème fraîche. Stir to combine and season with salt and pepper. Sprinkle with parsley and serve while piping hot.

Porcini and white polenta

This dish is delicate, and only really works as a first course as it is too insubtantial in flavour to satisfy as a main. At Petersham we buy only the white polenta, which is traditionally served with seafood in Italy's Veneto region. It is far superior to the yellow variety.

Serves 6

750ml/11/2 pints water
250g/8oz white polenta
75g/3oz unsalted butter
100g/31/2oz freshly grated Parmesan
Freshly ground black pepper
12 porcini

Place the water in a heavy-based pan, and bring to a vigorous boil. Season with a good pinch of sea-salt. Pour in the polenta, turn down the heat slightly and stir continuously for about 5 minutes with a wooden spoon, until the polenta resembles a thick, smooth porridge.

Remove from the heat and add the butter and Parmesan. Season with plenty of black pepper and add more salt if necessary. Pour into a bowl and keep warm in a bain marie (it will keep well like this for an hour or so).

Clean the porcini by trimming the ends and gently removing any dirt using a mushroom brush. Discard any porcini whose stalks are pitted with holes as this is an indication of the presence of maggots. Slice finely. Spoon the polenta onto the plates and scatter the porcini over the top. Eat while the polenta is piping hot.

Porcini, Parmesan and celery salad with walnut oil

I really love this salad and feel quite proud of it. I first made it last autumn with Ceasar's mushrooms - they are another delicious variety, but sadly hard to find this year. The new season's walnut oil works beautifully here. The flavour is light and delicate, yet unmistakably autumnal.

Serves 4

4 stalks celery (white part only), sliced very finely on the diagonal
100g/31/2oz Parmesan cheese, finely sliced
6 porcini, cleaned and very finely sliced
Freshly ground black pepper
A few drops of lemon juice
1tbsp extra-virgin olive oil
1tsp finely chopped curly parsley
1tbsp walnut oil

Place the finely sliced celery, Parmesan and porcini into a bowl and season lightly with salt and pepper. Squeeze over the lemon juice and drizzle over the olive oil. Toss lightly with your fingers. Divide among four plates. Sprinkle with the parsley and gently spoon over the walnut oil. Serve immediately.

Partridge and porcini on toast

Partridge are delicious at this time of year - look for the grey-legged variety, as I think they are much more delicious than their red-legged cousins.

Serves 4

1tbsp extra-virgin olive oil
4 grey-legged partridge
4 slices of crusty, white, peasant-style bread
8 porcini mushrooms
50ml/2fl oz red wine
100g/31/2 oz unsalted butter
Salt-salt and freshly ground black pepper

Pre-heat the oven to 190C/375F/Gas5. Season the partridge generously with salt and pepper. Heat the olive oil in a frying pan over a high heat. When the oil is hot, add the partridge, breast-side down, and cook for 3 to 4 minutes until golden brown. Turn and brown the other side. When done, remove the partridge and set aside. Next, place the bread in the same pan without cleaning the oil from it and fry for a few minutes. Then put the partridge on top of the bread and place the whole pan in the oven for 8 to 10 minutes.

Remove from the oven and take both the partridge and toast from the pan. Keep in a warm place. Return the pan to the stove over a medium heat; de-glaze with the wine, allowing it to bubble and reduce by two thirds. While the wine is reducing, quickly sautée the porcini in another pan with a little olive oil and some salt and pepper.

Place the partridge and toast onto a plate and spoon over the porcini. Add the butter to the wine, whisking quickly to amalgamate the sauce. Check for seasoning, as you may need to add a little more salt and pepper. Pour the sauce over the partridge and serve.

Q&A Skye answers your culinary queries

Q. I find it hard to find good-quality farmed rabbit. Can you help? Richard Mantell

A. We get all our rabbit from Albert the grouse man who works for Allen & Co, the butchers on Mount Street in London's Mayfair. If he can't get it for you himself, he'll know who can. You can reach him on tel: 07986 542 728.

Q. I never know: should vegetables be cooked in boiling water or cold? Tabitha Rolands

A. As a rule of thumb, any vegetables that grow above the ground go into boiling water and anything that grows under it goes in cold. Vegetables that grow above ground have a shorter cooking time and green vegetables need water that is as salty as the sea. I usually salt the water at the beginning of cooking and at the end. That way you shouldn't need to salt them again when they come out.

Q. Please could you tell me how you prepare polenta, as there seem to be so many different ways (grilled, wet, with cheese etc). Rosie Fickling

A. I don't like grilled polenta but that's just a personal thing. I always use one cup of polenta to four cups of water. When it's soft, finish it off with a knob of cold, unsalted butter and about 100g (31/2oz) of freshly grated Parmesan.