• 1 salmon or sea trout, about 900 g (2 lb), cleaned
  • 45 ml (3 tbsp) lemon juice
  • 50 g (2 oz) butter or margarine
  • salt and pepper
  • 1 bunch watercress, roughly chopped
  • 125 g (4 oz) spinach leaves, roughly chopped
  • 45 ml (3 tbsp) chopped parsley
  • 30 ml (2 tbsp) chopped chervil
  • 5 ml (1 tsp) chopped dill
  • 150ml ( 1/4 pint) Mayonnaise
  • TO GARNISH:
  • herb sprigs
  • lemon rind shapes

Place the fish in the centre of a large piece of foil. Add 30 ml (2 tbsp) of the lemon juice, then dot with 25 g (1 oz) of the butter. Season.

Seal the foil, weigh the fish and place on a baking sheet. Calculate the cooking time at 15 minutes per 450 g (1 lb), plus 10 minutes. Bake at 180°C (350°F) mark 4 until tender.

Remove the fish from the foil, reserving the cooking liquor, then carefully remove the skin while still warm. Place the fish on a serving dish and leave to cool.

To make the sauce, put the cooking liquor and the remaining 25 g (1 oz) butter in a saucepan and heat gently. Add the watercress, spinach, parsley, chervil and dill, then cook for 2-3 minutes or until softened.

Put the sauce in a blender or food processor and blend until smooth. Transfer to a bowl, add the remaining lemon juice and season to taste. Leave to cool, then fold in the mayonnaise. Turn into a small serving jug and refrigerate until required.

Garnish the fish decoratively with herbs and lemon rind shapes, and serve with the herb sauce.

Cal/Serv: 575