In a heavy, deep saucepan, melt the 1 stick of unsalted butter, slowly, so it does not brown.
While the butter is melting, cut the soften cream cheese into smaller chunks, so it will melt easier. Add to melted butter. Stir often, until melted with the butter. It will not blend smoothly with the butter at this point, so do not worry.
Add the parmedan cheese, and then slowly whisk in the milk, a cup at a time.
Add the garlic powder, and a pinch or two of nutmeg (fresh is preferred, but whats in your spice cabinet works too).
Let simmer on the lowest heat, until the sauce thickens to your desired consistency. It will thicken the longer it sets, but just add more milk, to get it back to what you want. Add fresh ground pepper to taste.
Serve with your favorite pasta and chicken. You can add your favorite herbs to this to jazz it up too. I have done chive, dill, or basil, depending on the meat I am serving it with.