Grease a 6×9 casserole dish. Preheat oven to 400 degrees.
Cook rice. While the rice is cooking, saute onion in olive oil. Add the spinach to the rice the last few minutes of cooking.
When the rice is done, add all the other ingredients (except the cheese) and mix well. Pour into casserole dish. Top with cheese and bake for 25 minutes.
