Chicken Casserole with Velveeta and Ritz

2-3 pounds boneless, skinless cooked chicken, cut in pcs.
Add 4 cups chicken broth, 1 can cream of mushroom soup (or cream of chicken), 3 eggs, well beaten, 1 tsp. salt, 1/2 tsp. pepper, 1-1/2 cup chopped celery, 1 small onion, 1-1/2 cup diced Velveeta cheese, 4 cup crushed Ritz crackers (save 1 cup for top). Mix all together and bake in 9 x 13 pan. Put crackers on top before baking. Bake at 350 degrees for 1 hour.