6 yellow squash, each cut lengthwise
1 small onion, chopped
1 can (15 oz.) tomato sauce
Dried oregano to taste
2-3 c. grated mozzarella cheese

Sauté small onion in butter. Add tomato sauce. Heat and boil 1 minute. Pour sauce over squash. Shake oregano over all. Top with lots of mozzarella cheese.

Bake at 350°F for 30-45 minutes or until squash is tender.