Heat a skillet or pot on medium low heat. Add the butter and whisk until melted, add in the flour and whisk until combined.
Slowly whisk in the milk a little at a time. Once all the half and half is whisked in reduce heat to low and let simmer just until thickened.
Whisk in the mustard, garlic powder, cayenne, until combined.
Turn off the heat and add the cheeses and whisk until melted.
Add in cooked pasta
Add salt and pepper to taste and serve!
Video
Notes
1. Any short pasta will work for this.2. Cook your pasta al dente, it will cook a tad more in the cheese sauce.3. Grate your own cheese by hand Pre shredded cheese is coated with starches and doesn't melt as well.4. American cheese can be found in the deli section of your grocery store.