Divide mushrooms and crayfish tails evenly among gratin dishes. Sprinkle each dish with 1/4 teaspoon cognac. Top each with 1 whole crawfish and garnish with parsley.

Crayfish, crawdads or crawfish are spicy tidbits of crustaceans, packed with flavor. They resemble tiny lobsters, weighing from one to two ounces. The only edible portion is the tail, although ...