Preheat oven to 325 degrees. Grease a large, deep casserole.
In a saucepan, place onions and add just enough water to barely cover onions and bring water to a boil. Boil only until onions are tender, about 5 minutes. Drain well.
In a prepared casserole dish, place a thin layer of each ingredient in the following order: onions, squash, zucchini, stuffing mix and stewed tomatoes. Repeat layering in the same order, ending with tomatoes. Sprinkle generously with cheese.
Bake in preheated oven for 30 minutes. Serve immediately. Makes 4-6 servings. Enjoy!
*Note: In a bowl, mix the stuffing mix with the herbs but DO NOT ADD ANY LIQUID to the stuffing. It should be dry.