Cut a cold cooked lobster in half lengthways; remove the claws and the flesh from the tail. Trim the flesh from the tail, cut it into even-sized fairly thick slices, coat with a thick layer of Fish Aspic Jelly and decorate each with a slice of grooved truffle. Finally, glaze the slices with a final coating of jelly.
Also glaze as many poached and dried oysters as there are slices of lobster, using the same jelly.
Pound together the creamy parts of the lobster and the flesh of the claws with a tablespoon of cold Sauce Béchamel. Pass through a fine sieve and with some melted Fish Aspic Jelly and cream, prepare a Mousse de Homard using a little paprika to give a nice pink colour. Fill the two half lobster shells with the Mousse and allow to set in the refrigerator.
When required, arrange the slices of lobster alternating with the oysters on top of the filled halves of lobster; place the halves back to back on a serviette on a dish with a heart of lettuce in the middle and sprigs of parsley at each end.
Serve accompanied with Sauce Mayonnaise or any other suitable cold sauce.