Meanwhile, in a pot of salted boiling water, cook the pasta until al dente.
Using a spider skimmer, transfer the pasta to the cheese sauce; alternatively, strain the pasta in a colander, making sure to first reserve 1 cup (240ml) of pasta-cooking water.
Add 1/4 cup (60ml) of pasta-cooking water to the pasta and sauce and, working over medium-low heat, stir gently until the pasta is coated in a creamy glaze. If the sauce becomes too thick, add more pasta water, 1 tablespoon (15ml) at a time, to loosen to a proper glazing consistency.
Season with salt to taste.