1.Melt butter in medium frying pan. Add cream; bring to a boil then reduce heat. Simmer, uncovered, about 5 minutes or until sauce reduces by half.
2.Add cheese; stir over low heat about 2 minutes or until cheese melts.
Use light thickened cream for a lower-fat version. Parmigiano reggiano, a salty, sharp, aged cheese, is best used in this recipe, and is available at most delicatessens. Do not reduce the cream mixture too rapidly or by too much as this sauce can burn.