Mexican Rice Casserole - With legumes

1 1/2 cups white rice , prepared per instructions 1 teaspoon olive oil 1 lb lean ground beef (I used 96/4) 1/2 yellow sweet onion , diced 3 garlic cloves ,[...]

3 -4 tablespoons oil 3/4 cup water 1 1/2-2 cups sliced fresh mushrooms (can use canned also) 2 green bell peppers , chopped 1 large onion , chopped 2 -3 fresh[...]