Panera Style White Cheddar Mac and Cheese

Panera Style White Cheddar Mac and Cheese 12 sides or 6 main dishes

16 oz   Pasta (shell, penne, gemelli, elbow, etc) 4 TBL butter 1/3 to 1/2 cup flour 2 1/2 cups heavy cream 4 oz white american cheese, chopped or torn in pieces 8 oz extra sharp white cheddar, shredded 1 TBL  Dijon mustard 1 tsp Kosher salt 1 tsp Frank's hot sauce pepper to taste
Cook pasta according to directions.  Drain well.
While the pasta cooks, melt the butter in a small sauce pan over medium heat.  When the butter has melted, whisk in flour.  Cook for 1 minutes whisking constantly.  Gradually whisk in the cream.  Whisk until there are no lumps.  Reduce heat to meduim-low and cook cream mixture, whisking frequently, until mixture thickens and bubbles, about 8 minutes.  

Remove from heat.  Gradually stir in the cheeses by the handful to allow the cheeses to melt before adding more.  

Stir in the mustard, salt, and hot sauce.  

Add pasta to the cheese mixture. Mix well.  Make sure to throughly coat all the pasta with the sauce.  Cook for an additional minute or two on medium-low heat until heated through.  Pepper to taste.
*When reheating leftovers add a little milk before heating.