Place a large skillet over medium heat and add butter.
Melt butter and add in the garlic. Cook and stir for 30 seconds until the garlic is fragrant.
Pour in the heavy cream, salt, black pepper and nutmeg, turn the heat down to medium low and bring the sauce up to a simmer. Continue to simmer the sauce, stirring continually, being sure to scrape down the sides as you stir, until the sauce thickens.
Remove the pan from the heat and stir in the parmesan cheese until it is melted and the sauce is smooth and creamy.