Original Mac Recipe

Bring a large pot of salted water to a boil. Add the elbow macaroni and cook until just shy of al dente (about 1 minute less than package instructions), about 7–8 minutes depending on brand. Reserve 1/2 cup of the pasta cooking water, then drain the pasta and set aside.

Roux

In a medium saucepan over medium heat, melt 3 tbsp unsalted butter. Once foaming, add 3 tbsp all-purpose flour and whisk constantly for 1–2 minutes until the raw flour taste cooks off and the mixture is a pale golden roux.

Add milk

Gradually whisk in 2 cups whole milk and 1 cup heavy cream, adding a little at a time to avoid lumps. Continue to whisk and bring the mixture to a gentle simmer; it will thicken slightly in 3–5 minutes.

Season

Whisk in 1 tsp Dijon mustard, 1 tsp Worcestershire sauce, 1 tsp kosher salt, 1 tsp black pepper, and a pinch of nutmeg (if using). Taste and adjust seasoning.

Incorporate cheeses

Reduce heat to low. Remove the sauce from direct heat and add 2 cups shredded sharp cheddar and 1 cup shredded mozzarella in small handfuls, stirring or whisking until each addition melts and the sauce is smooth. If the sauce is too thick, whisk in up to the reserved 1/2 cup pasta water, 1–2 tbsp at a time, until you reach a creamy pouring consistency.

Add the drained macaroni to the cheese sauce and stir gently until all pasta is evenly coated. Taste and adjust salt and pepper if needed. Transfer to an ovenproof serving dish if you plan to bake; otherwise keep in the saucepan for serving.

If you want a crispy top, preheat the broiler or oven to 425°F (220°C). In a small bowl, mix 3 tbsp panko breadcrumbs, 2 tbsp grated Parmesan, and 1 tbsp melted butter. Sprinkle the mixture evenly over the mac and cheese and place under the broiler or into the oven for 3–6 minutes until golden and crisp. Watch carefully to avoid burning.

Let rest 3–5 minutes so the sauce settles slightly. Serve hot straight from the pan or dish.