1-Get a large pot of salted water: Get a large pot of salted water boiling and cook your pasta al dente according to the directions it comes with.
2-Meanwhile, melt butter in a heavy bottomed: Meanwhile, melt butter in a heavy bottomed sauce pan over medium heat. Add minced garlic and pinch of salt and cook for 2 minutes or until softened but not browned.
3-Whisk in flour and let the roux: Whisk in flour and let the roux cook for 1-2 minutes or until the flour taste has disappeared.
4-Whisk in room temp milk and a: Whisk in room temp milk and a few pinches of salt then turn the heat to medium-low.
5-Let the milk simmer for 5-10 minutes: Let the milk simmer for 5-10 minutes so that it is thickened and slightly reduced.
6-Now whisk 1 cup of cheese (both: Now whisk 1 cup of cheese (both the regular and smoked gouda) at a time, little by little, until the sauce is smooth and creamy.
7-Add the dijon mustard and stir: Add the dijon mustard and stir. Season with salt and pepper to taste.
8-Mix in the pasta and season with: Mix in the pasta and season with salted and pepper before serving.