2 tbsp (1 oz) 25 g butter
1/3 cup (50 g) flour
2/3 cup (150 ml) 1/4 pt milk
3 tablespoons dry vermouth
100g (4 oz) peeled cooked prawns
100g (4 oz) scampi
4 oz (100 g) white fish fillets, skinned and chopped
3/4 cup (90 g) mushrooms, finely chopped
1 teaspoon lemon juice
rind of 1/2 lemon
salt and freshly ground black pepper
350g (12 oz) puff pastry, defrosted if frozen
1 egg, beaten, to glaze