First, you need a covered casserole to put this in. The rice needs to be covered to cook properly. That's a lesson I learned 5 years ago - on Christmas day. I had decided to make hubby's grandmother's brown rice recipe (another great recipe that I'll share at a later time). I had never made brown rice before, so I followed the recipe to the letter. Except... I forgot to put a lid on it. An hour later, when we had gummy, raw rice in a dish, I was devastated. Lesson learned. Casserole dish with a lid people. (Or you could tightly cover it with tin foil, but make sure its tight.)
OK, so now for the recipe. Preheat the oven to 350 degrees. Spread one cup of regular, long grain white rice in the casserole dish. Sprinkle 1 small to medium chopped onion on top.
Next, pour in one can of beef consomme and one can of French onion soup. Mix together.
Now, throw in one 6oz jar of sliced mushrooms (drained). (Try to make sure to distribute them evenly.)