Bring a large pot of salted water to a boil. Cook the macaroni according to the packet instructions until it’s just al dente. Before draining, reserve about ¼ cup of the pasta cooking water and set it aside.

In a medium saucepan over medium heat, melt the butter. Once melted, add the flour, stirring constantly for about 2-3 minutes until it becomes a pale golden color and gives off a nutty aroma.

Slowly whisk in the milk to avoid lumps, continuing to stir until the sauce thickens—this should take about 4 to 5 minutes.

Stir in the grated cheese, chicken stock paste, Dijon mustard, and a generous grind of black pepper.

Add the reserved pasta water to loosen the sauce for a creamier consistency. Taste before adding salt.

Turn off the heat and add the drained pasta to the cheese sauce, mixing until it’s fully coated. Let it rest for a minute before serving.

Serve immediately, garnished with extra black pepper if desired.