Boil a large pot of salted water. Cook the elbow macaroni according to package instructions until al dente. Drain well and set aside.

In a large saucepan or Dutch oven, melt the butter over medium heat. Whisk in the flour and cook for 1 to 2 minutes until light golden to create a roux.

Gradually whisk in the warmed whole milk, ensuring no lumps form. Simmer the mixture for 3 to 4 minutes until thickened enough to coat the back of a spoon.

Remove the saucepan entirely from the heat. Gradually stir in the freshly grated sharp cheddar cheese until fully melted and the sauce is smooth. Season with salt and black pepper.

Fold the cooked pasta into the warm cheese sauce until evenly coated. Serve immediately.