2 tbsp. chopped onion
1/4 c. butter
1/4 c. all-purpose flour
1 tsp. mustard
Dash of pepper
1 1/2 c. milk
2 c. shredded Cheddar cheese
2 c. cubed cooked ham
6 c. cubed cooked potatoes

Saute onion in butter in large saucepan until tender. Add flour, salt, mustard and pepper stirring until smooth. Cook 1 minute, stirring constantly. Gradually add milk; cook over medium heat, stirring constantly until thickened and bubbly. Add 1 1/2 cups cheese, stirring until melted. Add ham and potatoes, tossing gently.

Spoon into a greased 2 quart shallow baking casserole dish. Bake uncovered at 350 degrees for 25 minutes. Sprinkle with remaining cheese and bake an additional 5 minutes until cheese is bubbly and melted.