WHILE PLANNING a series of classes on the French island of Martinique in the Caribbean, I was inspired to take the classic quiche of the island’s motherland and combine it with the wonderful local seafood. Although I originally made this with langouste (rock lobster), which is plentiful in the Caribbean, I ultimately substituted crab, which is far more easily available elsewhere. Shrimp, scallops, lobster, or mussels can also be used with excellent results (see