Cooking Directions:
1. Preheat over to 375ºF.
2. Prepare pasta according to package directions.
3. In medium saucepan, over medium heat, melt butter; stir in flour and mustard. Gradually stir in milk; cook and stir until mixture bubbles. Remove from heat.
4. Add 1-1/2 cups cheese; stir until melted.
5. Stir in cooked pasta, ham, and corn; spoon into greased 13 x 9-inch baking dish.
6. Top with remaining 1-1/2 cups cheese. Bake 25 minutes or until bubbly.