Start by grating your parmesan cheese finely so it melts quickly and smoothly into the sauce. In a large skillet or saucepan over low heat, melt butter with the minced garlic, stirring occasionally until the butter is fully melted and the garlic is fragrant, about 5 minutes.
½ cup butter, 1 ½ cups Parmesan cheese, 3-5 cloves garlic
Stir in the heavy cream, salt, and pepper into the melted butter mixture. Let the sauce simmer for 5-8 minutes, stirring occasionally, until it reduces to your desired consistency. Keep the heat low to prevent the cream from breaking or curdling.
1 ½ cups heavy cream, Salt and pepper, Fresh parsley
Remove the pan from heat and gradually stir in the grated parmesan cheese until it's fully melted and the sauce is smooth. If the sauce seems too thick, whisk in a splash of milk or pasta water to thin it out. Garnish with fresh chopped parsley if desired and serve immediately over your favorite pasta.
Notes
Use freshly grated parmesan cheese rather than pre-shredded for the smoothest melting and best flavor
Cook on low heat throughout the process to prevent the cream from breaking or the sauce from becoming grainy
Grate the cheese finely so it incorporates quickly and evenly into the hot cream mixture
If the sauce gets too thick, add pasta water or milk one tablespoon at a time until you reach the desired consistency