Melt 2 tablespoons butter in a saucepan over medium heat
Stir in 2 tablespoons all-purpose flour
Cook for 1 minute, stirring constantly
Slowly whisk in 2 cups milk
Cook until the mixture thickens, stirring often
Lower the heat
Add 2 cups shredded cheese
Stir until the cheese melts completely
Season with salt and pepper
Mix with cooked macaroni
Serve immediately