In a small saucepan, melt butter; blend in flour and seasonings. Add milk slowly, and cook over low heat, stirring constantly until thickened. Remove from heat and add cheese; stir until melted. Put alternate layers of potatoes and ham in greased baking dish. Pour cheese sauce over top. Cover and bake at 350ยบ for 30 minutes. Remove lid and bake 10 minutes longer. Serves
4 to 6.