Put a pint of good bechamel (No. 154) into a saucepan, with four mushrooms, one truffle, and the meat from the claw of a cooked lobster, cutting them all into dice-shaped pieces. Thicken well and let cook for five minutes, and serve. If a lobster cannot be obtained, the meat of three cooked crawfish, or of six prawns or shrimps, may be used instead.