Brush the fish on one side with butter and season lightly with salt and pepper.
Put under a hot grill and cook until golden brown.
Turn over, brush with butter, season lightly and sprinkle with cheese.
Continue cooking until brown and tender.
Meanwhile, fry the almonds and mushrooms in the remaining butter.
Put the fish on to a hot serving dish and arrange the nuts and mushrooms round.
Garnish with tomato slices and sprigs of parsley.