1 med. onion, diced and sauted
1 (8 oz.) can water chestnuts, drained and chopped
2 (14 1/2 oz.) cans French cut green beans, rinsed and drained
1 (4 oz.) can pimentos, rinsed and drained
1 can cream of celery soup
1 cup mayonnaise
1 (6 oz.) box Uncel Ben's long-grain and wild rice, cooked according to pkg. directions
1 cup grated sharp Cheddar cheese