2Melt butter over medium heat in large saucepan. Once melted add flour and cayenne pepper to make a roux. Salt and pepper to taste. Cook roux until it takes a nice deep blonde color, about 5–7 minutes. Don’t let it get to dark (a dark roux won’t thicken properly).
3Add milk to the roux, half a cup at a time, stirring until smooth before adding next addition. The mixture should be smooth and thick. If it’s too thick, add more milk in 1/4 cup increments. If it’s too thin, you will have to start over.
4Once your bechamel is to your liking, begin to add the grated cheeses in small increments, stirring each addition until smooth and incorporated. When finished, reduce heat to low.
5Cook macaroni according to directions on box. Drain and rinse.
6Add cheese sauce to macaroni. Bake in ove proof dish for 30 minutes until slightly firm. Top with additional cheddar cheese if you like.