1/4 c. onion, chopped
1/2 c. butter
1 tsp. dry mustard
1 tsp. salt
1/8 tsp. pepper
3/4 c. milk
1/4 lb. Velveeta cheese
6 potatoes, cooked & grated

Saute onion and butter. Add the remainder of ingredients (all but potatoes). Cook on low heat until cheese is melted. Then pour on potatoes and mix gently. Bake at 350 degrees for 35 minutes.