Melt 3 tablespoons butter in a heavy skillet; sauté onion, zucchini, and celery until nearly tender and lightly browned, about 12 to 15 minutes.Combine with the turkey in a 3-quart baking dish. In the same skillet, brown the mushrooms, adding more butter if needed. Add to turkey mixture. Add carrots to casserole.
Stir wine into pan drippings in the skillet, then add the chicken broth, soups, thyme, and marjoram. Bring to a boil, stirring to loosen browned bits in the skillet. Pour sauce over turkey and vegetables; gently stir the mixture. Bake, covered, at 350° for 1 hour, or until bubbly in the center. If desired, sprinkle Parmesan cheese over the top before serving.
Serves 6.