Sole and Crayfish Tarts

• 12 crayfish, cooked in court-bouillon
• ¼ pint liquid in which crayfish were cooked
• 1

Pound cooked crayfish while still warm in a mortar with ¼ pint of the liquid in which they were cooked. Press through a fine sieve and reserve.

Simmer finely chopped onion in 1 tablespoon butter unt