Chef John's Macaroni and Cheese

Preheat oven to 400 degrees F (200 degrees C).

Fill a large pot with lightly salted water and bring to a rolling boil over high heat.

Once the water is boiling, stir in the macaroni, and return to a boil.

Cook the pasta uncovered, stirring occasionally, until the pasta is cooked through but still slightly firm, about 8 minutes.

Melt 1/4 cup butter in a large saucepan over medium heat.

When the butter starts to foam and bubble, stir in the flour; cook on medium heat until flour just begins to turn pale yellow, 3 to 4 minutes.

Add thyme, cayenne pepper, and white pepper; cook and stir another minute, then whisk in 1 cup of milk until smooth.

Pour in remaining milk and whisk again.

Bring the sauce just to a simmer.

Stir in nutmeg, Worcestershire sauce, and salt; simmer on medium-low heat until thickened, about 8 minutes, whisking often.

Turn heat off, then add 2 1/4 cups of Cheddar cheese; stir until melted and combined.

Add Dijon mustard.

Transfer the macaroni into a casserole dish, then pour in the cheese sauce; stir to thoroughly combine sauce with pasta.

Mix panko bread crumbs and 1 tablespoon melted butter in a small bowl, and sprinkle crumbs on top of macaroni and cheese.

Sprinkle remaining 3/4 cup of Cheddar cheese on top.

Bake in the preheated oven until bread crumbs and Cheddar cheese topping are golden brown, about 20 minutes.