Depending on how thick or thin of a sauce you like will depend on how much heavy cream you use add garlic to YOUR taste I love garlic so I use 2 heaping tablespoons.
Over medium heat in a saucepan melt 1 stick of butter and add the entire container of Parmesan cheese and begin to whisk.
Add garlic slowly.
Add heavy cream, again whisking until no longer lumpy. At this temp it should come to a boil on its own. When it does, slowly add more heavy cream until the consistency YOU desire, and then remove from heat.