Combine the chicken, lemon juice and grated onion.
Cover and marinate overnight.
Preheat oven to 350°F.
Combine the marinated chicken with the water chestnuts, almonds, pimento, celery salt, salt, pepper and mayonnaise.
Transfer the mixture to a baking dish.
Bake for 15 minutes.
Sprinkle the crumbled onion rings and grated cheddar cheese over the top.
Bake for approximately 10 more minutes.