Broccoli and Rice Casserole

4 cups cooked rice
2 pkg. chopped broccoli
1 16oz. Cheez Whiz
2 cans cream of chicken soup
1/2 cup milk
1 stick butter
1/2 cup each onion and celery

Saute onion and celery in butter, add rice and cooked broccoli and cheeze whiz. Add soup and milk and pour in baking dish and bake for 25 minutes at 350.