Heat the oven: Heat the oven to 400 F and grease a 2-quart baking dish.

Boil the water: Bring a large pot of salted water to a boil.

Add the macaroni: Add the macaroni pasta to the boiling water in the pot and cook the pasta until just shy of tender, then drain it well.

Start the sauce: Melt 3 tablespoons of the butter in a saucepan over medium heat, whisk in the flour, and cook for 1 minute until smooth and foamy.

Add the milk: Whisk in the milk gradually and cook, stirring often, until the sauce thickens enough to coat a spoon.

Melt in the cheese: Take the pan off the heat and stir in the cheddar, Monterey Jack, Dijon, paprika, 1 teaspoon of the salt, and the black pepper until smooth.

Combine the pasta: Fold the macaroni into the cheese sauce and scrape it into the prepared baking dish.

Top the pan: If you want a crisp top, toss the breadcrumbs with the remaining 1 tablespoon butter and scatter them over the macaroni.

Bake until bubbling: Bake for 15 to 20 minutes, until the edges bubble and the top is lightly browned.

Rest briefly: Let the macaroni and cheese sit for 5 minutes before spooning it into bowls.