Prepare all the ingredients.
Shell the langoustines.
Fry the scallops in olive oil.
Season and drizzle with the lemon juice.
Wash the hearts of lettuce...
...and place the nicest leaves in individual cups.
Distribute scallops, shrimp, langoustines and asparagus.
Sauce:: Mix the mayonnaise, ketchup, cognac and a few drops of tabasco.
Coat the shellfishes of sauce.
Decorate using chervil bits and serve.