Been making this for at least 20 years and it's hands down the best alfredo you will ever taste. Period. I will put this up against any restaurant's alfredo sauce... and win every single time.
4 cups heavy whipping cream
1/2 cup fresh parmesan
1 tablespoon blue cheese
1/8th teaspoon nutmeg.
Reduce your cream by a third on very low heat stirring occasionally. DO NOT turn your back on the pot. It will boil over faster than you can blink. When it's reduced, add everything else, give it a quick stir to melt the cheese and serve immediately. It does not keep and it doesn't reheat well. The butterfat tends to separate.. but this is the real deal.