In microwave-safe 9-inch deep dish, pie plate or shallow casserole. Arrange scrod in single layer. Sprinkle with lemon juice, salt, pepper and tarragon. Top each with tomato, onion and mushrooms; add wine. Cover loosely with plastic wrap; cook on High 11 to 13 minutes or until fish flakes easily with fork, rotating dish once. Meanwhile, in microwave-safe 4-cup measure, combine half and half and cornstarch until smooth; stir in shrimp. Drain liquid from scrod into measure. Cook on High 3 to 4 minutes or unti l thickened, stirring once. Pour sauce over scrod. Spread or decoratively pipe potatoes over sauce. Sprinkle with paprika. Cook on High 2 minutes to heat through. Makes 4 servings

* Or substitute for any white fleshed fish filet ** Mashed Potatoes: In microwave-safe bowl combine 1 1/4 cups hot water, 1/2 cup milk, 2 tablespoons margarine or butter and 1/2 teaspoon salt. Stir in 1 1/3 cups mashed potato flakes Cover loosely with plastic wrap; cook on High 2 to 3 minutes or until bubbly. Stir before using.