Fill a large pot with water and bring it to a boil. Add a generous amount of salt, then the elbow pasta. Cook until al dente, about 7-8 minutes. Drain and set aside.

In a large saucepan, melt the butter over medium heat. Add minced garlic and sauté until fragrant. Stir in the flour, creating a roux – a fancy term for a butter-and-flour mixture that thickens sauces. Cook for about a minute, ensuring it doesn’t brown.

Slowly whisk in the full-fat milk, making sure there are no lumps. Add the Dijon mustard and continue to whisk until the mixture begins to thicken, around 5-7 minutes.

Remove the saucepan from heat. Stir in the shredded mozzarella, grated sharp cheddar, and finely grated Parmesan. Add salt and freshly ground black pepper to taste. Mix until all cheeses are fully melted and the sauce is creamy.

Fold in the cooked pasta until each piece is well-coated with the cheese sauce. If you like a crispy topping, transfer the mac and cheese to a baking dish, sprinkle with toasted panko breadcrumbs, and broil for 2-3 minutes until golden.