01 -
Bring a large pot of salted water to a boil. Add the elbow macaroni and cook until al dente according to package instructions. Drain the pasta and set aside.
02 -
While the pasta is cooking, melt the butter over medium heat in a large pot. Reduce heat to low, then whisk in the flour and ground mustard to create a smooth paste. This creates the base for your cheese sauce.
03 -
Gradually whisk in the room temperature milk until smooth with no lumps. Turn the heat to medium and continue whisking until the sauce begins to thicken, about 2 minutes.
04 -
Stir in the shredded sharp cheddar cheese, continuing to stir until all the cheese is completely melted and the sauce is smooth and creamy.
05 -
Add the drained pasta to the cheese sauce and stir until all the pasta is well coated. Season with salt and freshly ground black pepper to taste. Garnish with additional shredded cheese and crushed saltine crackers if desired, and serve immediately while hot and creamy.