Mac and Cheese from Last Night's Dinner

1 lb. short, chunky pasta (usually I use ribbed elbow noodles from Trader Joes)
1/4 cup unbleached all-purpose flour
1/4 cup butter
2 cups milk
1/2 cup heavy cream
3/4 teaspoon dry mustard
Kosher salt and freshly ground pepper
Dash of cayenne pepper
4 cups assorted cheeses, shredded, grated or cut into small chunks- usually I use cheddar (curds from Trader Joes), beer cheese, and pecorino romano
several sprigs of fresh chopped rosemary
the original recipe calls for a panko topping but I have never done this

Cook the pasta according to package directions.

Meanwhile, melt 1/4 cup butter in a wide saucepan, stir in the flour, then whisk in the milk and cream until the sauce is smooth. Whisk in the dry mustard and hot sauce, and season with salt and pepper. Add the cheeses a little at a time, stirring until they are well incorporated. Taste and adjust seasoning if needed. Add the pasta to the cheese mixture and stir gently until the pasta is well coated with sauce.

Pour the pasta and cheese mixture into a lightly buttered baking dish. Sprinkle the rosemary evenly over the top of the pasta and cheese. Place the baking dish into a preheated 400 degree oven, uncovered, until the top is browned and the sauce is bubbling (about 20 minutes). Allow to sit 5 minutes before serving.