A Cornish tale: Skye Gyngell makes the most of the local produce at the Literary Festival

I have just returned from a glorious week in Cornwall. I spent it with family and friends walking, swimming and doing the occasional bit of cooking and was lucky enough to have avoided the awful weather in London. We stayed in a tiny hotel in Daphne du Maurier country, full of tiny coves with hedgerows stuffed with marjoram, fennel and wild sweet peas that strangely have no scent at all.

The week finished with a visit to the annual Port Eliot Literary Festival where I was due to give a cookery demonstration. I went the year before and was really excited at the prospect of returning. It's a quirky and much more intimate event than, say, the Hay Literary Festival. It's set in the grounds of the beautiful home of Cathy and Peregrine St Germans, and is a wonderfully cosy affair – full of charm, slightly chaotic and packed with children.

The house itself is beautiful. The kitchen has huge wooden fridges which would originally have been filled with ice and there's an incredible pantry filled with copper pans and pewter plates. I was on after a comedian and the whole thing was filmed by a local farmer who grew the heritage tomatoes that I used – you get the idea, it's unique.

A local company called Funky Leaves supply Jamie Oliver's Fifteen in nearby Watergate Bay. The fish came from Looe. We got a wild sea bass and the only turbot that had been caught in the last two weeks in the area as the weather has been so bad. (It was absolutely beautiful but it didn't fit in the oven, so we auctioned it off at the end of the cookery demonstration for £60.)

What strikes me about Cornwall – and I've been holidaying there for years – is how much exceptional produce it has. There's beautiful fish, potatoes and lovely dairy, but the pity is that it all gets sent up to London. If you want to find good produce, you really have to know where to look.'

Skye Gyngell is head chef at Petersham Nurseries, Church Lane, Richmond, Surrey, tel: 020 8605 3627. Her book 'A Year in My Kitchen', Quadrille, is the 2007 Guild of Food Writers' Cookery Book of the Year

Salt-baked wild sea bass with saffron aioli

Serves 6

For the aioli

3 organic free-range egg yolks
A pinch of salt
3 cloves garlic, peeled and crushed

The juice of one lemon

20 strands saffron
220ml/7floz extra-virgin olive oil

For the fish

1 wild sea bass, gutted but scales left on
1 lemon
A few sprigs wild marjoram
2 branches wild fennel
6kg/12lb very coarse-grain rock salt
500ml/17floz water

Heat the oven to 220C/425F/Gas7. Place the egg yolks in a bowl, add a pinch of salt, the crushed garlic and the lemon juice and whisk to combine. Place the saffron threads in a tablespoon of warm water and soak to soften.

Pour the oil over the yolks, as slowly as you possibly can, whisking continuously as you do so (sometimes it is easier to get someone to pour the oil for you while you whisk, or easier still, make the aioli in a blender. Continue to whisk until all the oil is incorporated – you should end up with a thick, unctuous, garlicky mayonnaise. Stir in the soaked saffron including the water that the strands were steeped in.

For the fish, wash and pat dry the sea bass. Slice the lemon into pinwheels and insert into the cavity of the fish. Add the marjoram and fennel fronds.

Place the salt in a bowl and add the water. Mix together with your hands, it should be the consistency of wet sand.

You will need a roasting tray large enough to hold the whole fish. Lay half of the wet salt on the base of the tray, place the fish on top and cover with the rest of the salt moulding it into the body of the fish (a bit like if you are burying someone in the sand at the beach). You want to seal the fish in as snugly as possible so that it steams within its salt case.

Place in the hot oven and roast for 15 minutes or until the fish is hot to the bone (you can test this by inserting a sharp knife into the thickest part of the fish – if the point of the knife is warm the fish is cooked through).

Remove from the oven and leave to rest for 5 minutes; the salt will have set hard and you will need to crack it open with the blunt end of a knife.

Gently peel off the skin, the fish underneath will be wonderfully succulent. Serve with the saffron aioli and a large wedge of lemon.

Potatoes with beanshoots

We were supplied with potatoes from the farm on the estate at Port Eliot. The peashoots came from the garden at Petersham.

Serves 6

1kg/2lb potatoes
Enough water to cover the potatoes
A good pinch of salt
60ml/21/2 tbsp extra-virgin olive oil
The juice and zest of one lemon
1tbsp freshly grated Parmesan
2 handfuls peashoots, or if not, watercress is a good substitute

Scrub the potatoes to remove any dirt and place in a saucepan large enough to hold them comfortably. Cover with cold water and add a good pinch of salt.

Place over a medium flame and bring to the boil, turn the heat down slightly and simmer until the potatoes are really tender and almost falling apart. Drain and dress while still hot with the extra-virgin olive oil, lemon juice and its zest and the Parmesan. Toss with a spoon to make sure it is well combined.

Taste, and add a little salt if necessary and plenty of freshly ground black pepper. Just before serving toss through the peashoots and serve with the fish.

Salad of samphire, heritage tomatoes and burrata

This is a very simple salad. The samphire came from Looe and the edible flowers were a combination of borage, hollyhocks, marigolds, nasturtiams and violets, all from the Port Eliot estate.

Serves 4

A handful of samphire (approx 160g/5oz)
Sea-salt and freshly ground black pepper
2tbsp extra-virgin olive oil
4 ripe tomatoes
1 burrata (a type of south Italian soft cows' milk cheese) or buffalo mozzarella
The juice and zest of one lemon
A large handful of edible flowers

Bring a pan of salted water to the boil. Trim the woody stalks and drop the samphire in to it. Cook for a minute. Drain and dress while warm with half a tablespoon of olive oil.

Slice the tomatoes and season with sea-salt and black pepper and put on a plate. Tear the cheese with your hands and place with the samphire on the tomatoes. Dress with the lemon and olive oil. Scatter over the flowers. Serve immediately.

The Forager by Wendy Fogarty

Petersham's food sourcer reveals the best places to find Cornish produce...

It can be difficult to find local produce in Cornwall but the following can help locate the region's extraordinary bounty.

Fresh fish from Looe: Chris Dominic catches fish sustainably from his inshore day boat. He also sources fish from fellow day boats, smoking them when stocks are abundant, including mackerel, pollock and whiting. Tel: 01579 321 715 for stockists.

Cornish pilchards: The commitment of Nick Howell has preserved the artisan method of salting the fish. Tel: 01736 332 112, www.pilchardworks.co.uk

Seriously Good: Angie Dodd and partner aim to make quality local food more accessible from vegetables and fruit, to meat, fish and dairy. Tel: 01208 873 843, www.seriously-good.co.uk

Keveral Farmers Ltd: Supplies of organic, locally grown vegetables www.keveral.org. Tel: 01503 250 135, www.keveral.org

Funky Leaves: (www.funkyleaves.co.uk) supplied the edible flowers.