First let me say this recipe is not for the person who is on a diet! It is loaded with fat and is a comfort food. Sometimes I add a can of mushrooms to the recipe. You can also sprinkle parmesean cheese over the top of vegetables at the end of cooking time. You can use larger zucchini but depending on the size of the zucchini you might want to cut the slices in quarters. I have been making this for my family for years and they love it!