Boil potatoes until firm in texture, drain. In frying pan, saute 1/2 of onions in oil, butter, or bacon drippings. Add chunked boiled potatoes and saute until potatoes are slightly browned. Pour into a 9 x 11 x 2-inch or approximate size baking dish sprayed with a non-stick cooking spray. In same frying pan, saute remaining onions. Add zucchini and green squash, garlic, salt, and pepper. When finished, add to the potato mixture. Cover and place in refrigerator overnight. In the morning, remove from refrigerator. Beat egg mixture and add water, salt and pepper, and hot sauce to taste. Pour egg mixture over the sauteed ingredients. Place in pre-heated, 350-degree oven for about an hour. The last fifteen minutes of cooking, sprinkle the cheddar cheese over the top of the mixture. Slice and serve. Can be reheated in a microwave.