Bring a large pot of salted water to a rolling boil. Add the elbow macaroni and cook until al dente, about 7 minutes. Drain and set aside.

In a large saucepan, melt the butter over medium heat. Whisk in the flour and cook for 2-3 minutes until bubbly.

Gradually whisk in the whole milk, stirring continuously until the mixture thickens into a smooth sauce, about 5-7 minutes.

Lower the heat and stir in the shredded cheddar and Gruyere until melted. Add Dijon mustard, salt, and black pepper.

Add the cooked macaroni to the cheese sauce, mixing to coat every piece.

Transfer to a greased baking dish, sprinkle with breadcrumbs, and bake at 350°F for about 20 minutes.

Garnish with parsley or chives and smoked paprika. Serve hot.