Ingredients:
1 pound peeled crawfish tails 
1 cup water 
1 tablespoon corn oil margarine 
2 tablespoons flour 
1/2 teaspoon dijon mustard 
1/4 teaspoon salt 
1/4 teaspoon cayenne pepper 
1/2 teaspoon paprika 
3/4 cup non-fat dry milk plus water to yield 1 1/4 cup 
1 1/2 cup sliced fresh mushrooms 
1 tablespoon margarine 
2 tablespoons lemon juice 
1/4 cup grated swiss cheese 
2 tablespoons grated cheddar cheese 
3 tablespoons cracker crumbs

Directions:
Cook crawfish in water for 15 minutes. Drain and discard liquid. Melt margarine in heavy saucepan. Add flour and seasonings; blend well. Add milk, stirring constantly until sauce thickens. Add sautéed mushrooms, lemon juice and crawfish to sauce. Mix well and serve.