San Antonio Squash Casserole

2 tablespoons butter or margarine
2 cups yellow onion, diced
4 pounds yellow squash, sliced 3/8 inch thick
8 ounces Velveeta, cut in 3/4 inch cubes
1 cup cream of celery soup (undiluted)
1 cup green chiles, diced
1/2 cup bread crumbs
Parsley for garnish

Preheat oven to 350 degrees. In a 14-inch pan, saute onion in butter. Add squash and cook until slightly softened. Squash will release a lot of water, which must be drained. Mix squash and onion with cheese, soup, and green chiles and place in oiled casserole dish. Cover with bread crumbs and bake about 30 minutes or until hot throughout. Garnish with parsley and serve. Makes 10 big servings.