1 (10 oz.) pkg. frozen chopped broccoli
1/2 c. chopped onion
1/2 c. butter
1 1/3 c. cooked rice
1 (8 oz.) jar Cheez Whiz
1 (10 3/4 oz.) can cream of mushroom soup

Combine broccoli and onion; cook according to package directions. Drain and add remaining ingredients; stir well. Pour into a greased 2 quart shallow casserole. Bake at 350 degrees for 30 minutes.