Melt butter in a large Dutch oven over medium heat. Once melted, add in the finely minced garlic and sauté for 1 minute until fragrant. Sprinkle in the all-purpose flour and cook, stirring frequently, until the roux begins to turn golden brown. This will take approximately 2-3 minutes.
3 tablespoons butter, 2 cloves garlic, 3 tablespoons all-purpose flour
Slowly pour in the water while whisking continuously to break up any lumps that form. Then, pour in the milk and continue whisking until the mixture is smooth. Season the liquid with kosher salt and let it come to a gentle simmer. Once it starts simmering, reduce the heat to medium-low.
4 cups water, 2 cups milk, 1 teaspoon kosher salt
Stir in the cavatappi pasta and make sure it is fully submerged in the liquid. Cover the Dutch oven with the lid and cook pasta for 10-15 minutes, stirring occasionally to prevent sticking. The goal is to cook the pasta until it is al dente. When the pasta is finished cooking, remove the Dutch oven from the heat.
1 pound cavatappi pasta
Note: If you find that the pasta is drying out too quickly, you can add more water in ¼ cup increments. There should be a small amount of liquid remaining in the pot when the pasta finishes cooking.
Fold in the shredded white cheddar cheese, grated parmesan cheese, dijon mustard, and freshly ground black pepper. Continue stirring until all the cheese has fully melted, and the pasta is well coated in the creamy sauce. Garnish with some additional shredded cheese, chopped fresh herbs, or toasted breadcrumbs, if desired, and serve immediately.
1 teaspoon dijon mustard, 1 teaspoon black pepper, 4 cups sharp white cheddar cheese, ½ cup parmesan cheese