Panera Bread's Signature Macaroni & Cheese

** Recipe from Panera Bread **

* 1 (16 oz.) package of rigati pasta (or other small pasta shells)
* ¼ c. butter
* ½ c. all-purpose flour
* 2½ c. 2% reduced fat milk (or cream)
* 6 slices white American cheese, chopped
* 1 c. (8 ounces) shredded extra-sharp white Vermont cheddar
* 1 Tbl. Dijon mustard
* 1 tsp. kosher salt
* ¼ tsp. hot sauce

Prepare pasta according to package directions.  Melt butter over low heat. Whisk in flour and cook 1 min, whisking constantly.  Gradually whisk in milk (or cream); cook over medium heat, whisking until mixture thickens and bubbles. Remove from heat.  Add cheeses, mustard, salt, and hot sauce, stirring until cheese melts and sauce is smooth.  Stir in pasta and cook over medium heat for 1 min. (or until thoroughly heated).