Slices fish smeared with butter, add salt and sprinkle with pepper. Each is wrapped with aluminum foil and bake at BBQ 5 minutes on each side (or broil in the oven for 8 minutes on one side and the other side). In the pot is broken water bath two yolks, add lemon juice, a pinch of salt, a pinch of black pepper, 1/2 tsp water and the butter. He fought the fire until the initial rising. Before serving, unwrap the fish and pour the sauce.