Barbue au Pecheur

• 2 pounds brill
• 3 potatoes
• ½ pound mushrooms

Dice and parboil potatoes. Wash and dice mushrooms. Melt 2 tablespoons butter in a thick-bottomed frying pan; add the potatoes and let them cook slowly with the lid on until almost done. Then add diced mushrooms, season to taste with salt and freshly ground black pepper, and cook until tender.