The Welsh call sea trout ‘sewin’ and they come mainly from the fast-flowing rivers of Wales. Their pink flesh and delicate flavour are admirably complemented by the pretty green sauce.

Ingredients

Serves: 4
900 Gram Sea trout, cleaned (2 lb)
3 Tablespoon Lemon juice
50 Gram Butter (2 oz)
1 Bunch Watercress, roughly chopped
110 Gram Fresh spinach leaves, (4 oz) roughly chopped
3 Tablespoon Fresh parsley, chopped
2 Tablespoon Fresh chervil, chopped
1 Teaspoon Fresh dill, chopped
150 ml Mayonnaise (1/4 pint)
Fresh herbs & whole unpeeled cooked prawns

Method

Pre-heat the oven to 180 °C / 350 °F / Gas 4.
Place the fish in the centre of a large piece of foil. Add 2 tablespoons of the lemon juice, then dot with 25g (1 oz) of the butter. Seal the foil, weigh the fish and place on a baking sheet. Calculate the cooking time at 10 minutes per 450g (1 lb). Bake until tender. Remove the fish from the foil, reserving the cooking liquor, then carefully remove the skin while still warm. Arrange the fish on a serving dish and leave to cool.
To make the sauce, put the cooking liquor and the remaining butter in a saucepan and heat gently. Add the watercress, spinach, parsley, chervil and dill, then cook for 2-3 minutes, until softened.
Put the sauce in a food processor or blender and work it until smooth. Transfer to a bowl and add the remaining lemon juice. Leave to cool, then fold in the mayonnaise. Turn into a small serving bowl and chill until required. When the fish is cold, garnish with fresh herbs and whole prawns, if liked. Serve with the herb sauce.