Cook the pasta in a large pot with plenty of salted water following the time on its package instructions but minus 1-2 minutes for an al dente texture.The pasta will continue to cook in the sauce, so undercooking it by a minute or two is important to avoid mushy pasta.
Make the Cheese Sauce
While boiling the water to cook the pasta, shred the cheese and mix it. Reserve 1-2 cups to the side as a topping (if you plan to bake it).
Melt the butter in a large saucepan over medium heat. Once hot, sieve in the flour and whisk well for about a minute.
Slowly/gradually pour in the cream and milk while constantly whisking to ensure a smooth sauce. Continue to cook, whisking very often, until it thickens.
Remove the pan from the heat and stir in the cheese in 2-3 batches, stirring carefully between each one (this method helps avoid graininess/separation). Then season to taste with salt, pepper, and optional mustard powder. It should be smooth and delicious.If the sauce is too thick, add a little more milk. If it's too thin, continue to simmer it for slightly longer.
Drain the pasta, toss it into the sauce, and stir well to combine. You can optionally serve it immediately or go on to the next step for a mac and cheese bake.
Bake It (Optional)
Transfer the pasta to an oven-proof baking dish, sprinkle the top with the remaining grated cheese, and bake it at 325ºF/160ºC until it melts and is cheesy, bubbly, and golden brown (about 15 minutes).For crunchy texture, sprinkle over some dried bread crumbs (regular or panko) before baking.
Notes
Store any leftovers in an airtight container in the fridge for up to 5 days. For longer storage, freeze the pasta in a freezer-safe baking dish or portion it into Ziplock bags (excess air removed) for up to 4 months. Allow it to thaw in the refrigerator before reheating.Other add-ins & Recipe Variations:
Other seasonings: Increase the flavor complexity with paprika, garlic powder, cayenne pepper/ red pepper flakes (for heat), dried herbs, etc. Season to taste.
Sauces: Stir in some pesto, buffalo sauce, or salsa.
Add-ins: shredded chicken, sausage, tuna, peas, corn, cooked broccoli, cauliflower, sauteed mushrooms, spinach or kale, chili beans, sliced jalapenos, etc.
Check the blog post for more tips and serving recommendations!