Chicken and Broccoli Rice Casserole

1/2 cup chopped onion

1/2 cup sliced fresh mushrooms

1 tbsp. butter

 2 cups hot cooked rice

2 cups cubed cooked chicken

2 cups chopped cooked fresh broccoli, or 1 pkg. (10 oz.) chopped frozen broccoli, cooked

1 can cream of mushroom soup

1/2 cup shredded Cheddar cheese (I like more)

 Cook onions and mushrooms in large skillet with butter. Stir in rice, chicken, broccoli and soup. Pour into a buttered 1-1/2 to 2 quart casserole dish. Top with cheese and bake at 350 for 25 minutes, uncovered.