Instructions: Place the potatoes and stock in a saucepan and bring to the boil.

Cook for about 10 minutes or until the potatoes are almost tender.

Add the leeks peppercorns and plenty of salt.

Stir then cut the salmon into large chunks and place these on top.

Cover and simmer for 10-12 minutes over a low heat until the fish is just cooked.

Do not stir or the fish will break up.

Meanwhile make the pesto: place the first 4 ingredients in a food processor and process briefly until the sorrel is chopped.

Slowly add enough oil (through the feeder tube with the machine running) until it has the consistency of a thick paste.

Season with salt and pepper according to taste.

Alternatively this can all be done by hand with a pestle and mortar.

To serve taste the soup then season.

Ladle into warmed soup bowls then top with about 1/2 tbsp of the sorrel pesto.

Offer extra pesto in a bowl at the table.

If you have difficulty obtaining sorrel then grow it yourself: from seed to harvesting it can take as little as 34 weeks. Telephone Jekkas Herb Farm (01454 418-878) for details of its mailorder seeds.

Serves 4

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