Directions

1. Bring 4 quarts of water to a boil in a Dutch oven over high heat.
2. Add the macaroni and 1 tbsp. salt
3. cook until the pasta is tender.
4. Drain the pasta and set aside in a colander.
5. While the pasta is cooking, pour the milk into a small saucepan and gradually warm over medium/medium-low heat.
6. In the now-empty Dutch oven, heat the butter over medium-high heat until foaming and lightly browned.
7. Add the flour, mustard powder and cayenne pepper (if using) and whisk well to combine.
8. Continue whisking until the mixture becomes fragrant and deepens in color, about 1 minute.
9. Slowly add the warm milk while whisking constantly. Bring the mixture to a boil. (Mixture must reach a full boil to thicken.)
10. Reduce the heat to medium and simmer, whisking occasionally, until thickened to the consistency of heavy cream, about 5 minutes.
11. Remove the Dutch oven from the heat and whisk in the cheeses and 1 tsp. salt. Continue whisking until the cheeses are fully melted.
12. Stir in the pasta and mix well.
13. Pour the mixture into a 9 x 13" baking dish.
14. In a medium bowl, mix together the panko breadcrumbs and melted butter until well combined.
15. Evenly sprinkle the breadcrumb mixture over the macaroni and cheese.
16. Bake at 350°F for about 30 minutes, until the top is golden brown.
17. Serve as a main dish or a side.