Stuffed Jumbo Shells

2 cups cooked chicken or turkey, diced
1 can peas, drained
1/2 cup mayonnaise
1/4 cup chopped onion
1 can cream of chicken soup mixed with 1/2 cup water
12 ounces jumbo shells

Cook shells until barely soft. Mix all other ingredients. Stuff shells with filling mixture and put into casserole. Sprinkle lots of grated cheese over the top. Bake at 325 degrees F for 25 minutes.