Preheat oven to 375 degrees. In a large stockpot, boil mirlitons in water until fork tender. Cut them in half, peel, remove the large seed, and coarsely chop the flesh. In a large nonstick pan, saute mirlitons and shrimp in margarine for about 3 minutes. Add dry seasonings and cook for about 3 more minutes; remove from heat. Add crabmeat and 1/2 cup bread crumbs – mix well. Place mirliton dressing a 9 x 13 baking dish. Sprinkle remaining breadcrumbs and Parmesan cheese on top – dot with butter. Bake for 40-45 minutes. This dressing is delicious as a main course or side dish.
Variation: You can use crawfish tails in place of the shrimp – add them when you add the crabmeat since they are pre-cooked.