Chicken Chow Mein Casserole

2 (10 1/2 ounces) cans cream of mushroom soup
1 (3 ounce) can chow mein noodles
1 can or bag cashew nuts
2 cups diced chicken
1/2 cup water
1 1/4 cups celery, cut up
1/4 cup chopped onion
Dash pepper

Combine water and soup; blend. Reserve 1/2 of noodles for top of casserole. Add other noodles to soup mixture with celery, nuts, onion and chicken and toss lightly. Put reserved noodles on top. Bake for 20-25 minutes in 375 degree F oven.