Tuna and Rice Casserole 1 (6 ounce) can chunk light tuna in water, drained 1 cup frozen peas 1 can cream of mushroom soup 1 soup can milk 1/2 cup chopped onion 1 1/2 cups instant rice Combine all ingredients in a large mixing bowl. Place in 2-quart casserole dish. Bake covered at 350 degrees F for 45 minutes. Yields 4 servings.