For Marilyn, a pretty damn good macaroni and cheese recipe from the March 2008 issue of Fine Cooking. The author gives the serrano chiles and the crushed red pepper additions as separate suggested variations (along with pancetta, something I might try next time), but I liked it enough with both that I wouldn't consider leaving them out.
kosher salt
6 tbs unsalted butter
1 medium onion, finely diced
a few fresh serrano chiles, minced (~3 tbs)
6 tbs flour
1 tbs dijon mustard
1/4-1/2 tsp crushed red pepper
1 quart whole milk, heated
1 large sprig fresh thyme, plus 1 tsp chopped thyme leaves [I suggest more thyme]
1 bay leaf
8 oz (2 packed cups) grated extra-sharp white cheddar (sharpest you can find)
4 0z (1 packed cup) grated Monterey Jack
1/2 tsp Worcestershire sauce
1/2 tsp. Tobasco sauce
freshly ground black pepper
1 lb elbow macaroni [I used penne because it was what we had]
2 tbs extra-virgin olive oil; more for the baking dish
2 cups fresh breadcrumbs [do make your own breadcrumbs; this is crucial]
1 1/2 oz (1/2 lightly packed cup) freshly grated Parmigiano-Reggiano
Heat the oven to 400 F and put a large pot of well-salted water on to boil over high heat. Brush a 9x13 inch baking pan lightly with olive oil.
Melt the butter over high heat in a large, heavy-bottomed pot. Add the onion, serranos, and 1/2 tsp salt and cook, stirring occasionally with a wooden spoon, until softened, 4-5 minutes. Add the flour and cook, stirring, until slightly darker, 1-2 min. Stir in the mustard and crushed red pepper flakes. Switch to a whisk and gradually add the milk, whisking constantly.
When all the milk is in, switch back to the spoon and stir in the thyme sprig, bay leaf, and 1/2 tsp. salt. Let come to a bare simmer, and cook, stirring frequently, for 15 minutes to meld the flavors (reduce the heat to medium low or low as needed to maintain the bare simmer).
Discard the thyme sprig and bay leaf. Add the cheddar and jack cheese, stirring until melted, and then add the Worcestershire and Tabasco. Season to taste with salt and pepper. Keep warm, stirring occasionally. [better yet, time the sauce to finish at the same time the pasta is ready]
Cook the pasta in the boiling water until al dente [the chewy side of al dente, in my opinion, since you're going to bake it in cheese sauce]. Drain well and add to cheese sauce, stirring. Generously season to taste with salt and pepper. Transfer pasta into baking dish.
In a medium bowl, toss the breadcrumbs with the Parmigiano, olive oil, chopped thyme, 1/2 tsp salt, and 1/4 tsp pepper. Scatter evenly over pasta and bake until top is golden, about 15 minutes. Let rest 5-10 min before serving.