Tear spinach into bite sized pieces, removing stems and set aside.
In a large saucepan, saute onion in olive oil until tender. Add rice. Cook, stirring constantly, for 2 minutes. Add chicken broth and water; bring to a boil. Reduce heat, cover and simmer for 15 minutes.
Stir in spinach, salt and pepper and cook until spinach is wilted.
Transfer mixture to a 2 quart prepared baking dish. Sprinkle with cheese.
Cover and bake at 375 for 20-25 minutes or until rice is tender. Remove lid and turn oven to broil to brown cheese a bit.