Broccoli and Rice Casserole

2 bags frozen broccoli
3 c instant rice
1 can each: cream of mushroom, cream of chicken
3/4 c water
1/2 block Velveeta, cubed
1/2 celery stalk
1/2 onion
1/2 stick butter
* Sauté celery/onion, set aside
* prepare rice and broccoli according to pkg
* combine soups and water in sauce
Cook on low, stirring until hot. Add Velveeta gradually, stirring constantly. Do not burn.
Combine everything. Bake 45 minutes