Heat oven to 350 and cook pasta until al dente.
In a large saucepan, melt butter over medium heat.
Saute garlic for thirty seconds.
Add in flour, salt and pepper, whisking constantly.
Once flour mixture is smooth, gradually add in milk, a little bit at a time while stirring constantly with a whisk.
Bring to boil for one minute.
Add in mustard and Colby cheese, then continue to cook until cheese is melted through.
Mix together with cooked pasta and ham, then pour into 2 quart baking pan.
Sprinkle with Parmesan cheese and bake for 20-25 minutes, until bubbly. Enjoy!