Boil 2 pounds of diced zucchini and 1/4 cup chopped onion in 1 cup water for 5 minutes. Drain. Stir in 1 can cream of chicken soup, 1 cup sour cream, 1 cup shredded carrots, 1/2 teaspoon garlic salt. Toss contents of 1 package (8 ounce) herb-seasoned stuffing mix with 1/2 cup melted butter. Spread 1/2 of stuffing mix in bottom of 9 by 13 pan or large casserole dish. Spoon vegetable mixture over stuffing. Top with remaining stuffing mix. Bake 350 degrees for 25 to 30 minutes.