Broccoli Rice Casserole

10 oz (3 packets) frozen broccoli
10 oz (2 cans) cream of chicken soup
8 oz (1 jar) Cheese Whiz
3 c. cooked rice
3 tbsp butter
1 large onion, chopped

Preheat oven to 350 degrees. Sauté the onion in butter until it turns transparent. Add the frozen broccoli, cooking over a low heat until the broccoli is tender. Add chicken soup, Cheese Whiz, and cooked rice. Pour into a three-quart casserole dish. Bake for 25-30 minutes or until bubbly.