Choose a cheese that melts well, such as cheddar, Gruyère, Monterey Jack, fontina, or mozzarella
Grate the cheese finely
Make a roux by melting butter and whisking in flour
Slowly whisk in milk or cream until smooth
Cook the sauce until slightly thickened
Remove from heat
Stir in the grated cheese gradually
Mix until fully melted and smooth
Season with salt, pepper, mustard powder, or garlic powder if desired
Combine the cheese sauce with cooked pasta
Stir until the pasta is evenly coated
Serve immediately or bake with extra cheese on top if desired