Fry flour, cool, dissolve with a part of warm milk. Then mix it with the remaining milk, salt, sugar and cook through for 5-10 minutes. Filter the sauce and cook through again.

Cook crayfishes in salted water, halve, take the flesh out of the shell.

Mince and fry mushrooms, mix them with a part of milk sauce, dress with butter, salt and pepper.

Fill in the crayfish shells with prepared mixture, place in the baking mold, pour with the remaining sauce, season with grated cheese, sprinkle with melted butter and bake on strongly heated oven.

Top the crayfishes with olives and serve on a platter.