2 tbsp. chopped onion
1/4 c. butter
1/4 c. flour
1 tsp. salt
1/2 tsp. dry mustard
Dash of pepper
1 1/2 c. milk
2 c. (8 oz.) shredded mild Cheddar cheese
1/2 lb. ham, cut in 1/8 inch slices
6 c. cooked potato slices

Saute onion in butter. Blend in flour and seasonings. Gradually add milk, cook stirring constantly until thickened. Add 1 1/2 cups cheese. sTir until melted. toss potatoes in cheese sauce. Pour into 2 quart casserole, reserving 1 cup potato slices. Arrange ham and remaining potato slices on top of casserole. Bake at 350 degrees for 30 minutes. Top with remaining cheese.