The chicken is boiled in salted water and boned meat cut into cubes. Flour fry in half of the butter and pour 2 cups broth from cooking the chicken (broth has cooled down, otherwise the sauce becomes lumpy). Mushrooms cut into strips and fry in remaining butter to soften. Egg whites are broken down into snow and grated cheese grater in large pieces. To the cooled sauce add the chopped meat, mushrooms, cheese, beat egg yolks, salt and pepper to taste. Finally, gently, stirring with a wooden spoon, add the beaten whites. Pour the mixture into an oiled tray high, because in baking Plunk. Bake at 200 C for about 50 minutes.