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.