1 tsp. chopped onion
1/4 c. butter
1/4 c. flour
1 tsp. salt
1 tsp. pepper
2 c. milk
1 c. grated cheese
5 c. sliced potatoes
2 c. diced ham
1/2 c. chopped green pepper
1/2 c. chopped celery

Layer potatoes, ham, pepper and celery in baking dish. Pour thickened sauce over top. Bake in 350 degree oven for 1 1/2 hours. (Allow a lot of time to prepare).