Squash Casserole

6 to 8 yellow summer squash sliced
3 tablespoons of butter
1/2 cup onion diced
1 can cream of mushroom or cream of chicken soup
1/2 soup can filled with milk
1 cup shredded cheddar or American cheese
1 can Durkee French fried onions

Melt butter in a pan over medium heat. Add squash and onion. Cook just long enough for squash to get tender. Remove from heat. Stir in soup, milk, 1/2 cup of cheese, and 1/2 can of Durkee onions. Pour in a casserole dish. Top with remaining cheese and Durkee onions. Bake at 350 about 35 to 40 minutes. YUM!