Broccoli and Cheese Casserole

I think just about everyone has a variation of this recipe, but this is ours.

1 small jar cheese whiz (I can only find the large jars so I just don't use it all, and my mom has used velveeta)
1 box frozen chopped broccoli (again, I can only find the bags now, so I just use that)
1/2 stick butter
1 c cooked rice
1 can cream of mushroom soup

Thaw broccoli, then mix with butter and cream of mushroom soup. Simmer and add rice to the mixture. Stip in cheeze whiz until melted and combined well. bake at 350 for 30 minutes.