Place the heavy whipping cream and butter in a medium saucepan over medium heat.
Stir frequently until the butter melts completely.
Bring the mixture to a simmer.
Add the Parmesan, mozzarella, provolone, and Romano cheese gradually while stirring.
Lower the heat to low.
Stir constantly until the cheese melts completely.
Remove from heat and serve immediately.
Notes
Tips and Tricks
Use Freshly Grated Cheese - Pre-shredded cheese contains anti-caking agents that can make the sauce grainy. Grate your own cheese for the smoothest results.Keep the Heat Low - Once you add the cheese, keep the heat on low. High heat can cause the cheese to separate and become oily instead of creamy.Stir Constantly - Don't walk away from the stove once you add the cheese. Constant stirring helps the cheese melt evenly and prevents burning.Serve Immediately - This sauce is best right after you make it. It thickens significantly as it cools, so serve it hot over freshly cooked pasta.Add Pasta Water - If the sauce gets too thick, add a tablespoon or two of pasta cooking water to thin it out and help it coat the noodles better.Room Temperature Cheese - Let your cheese sit out for 15-20 minutes before using it. Cold cheese takes longer to melt and can cause the sauce to seize up.
Storing and Reheating
Store in Refrigerator - Place leftover sauce in an airtight container and refrigerate for up to 3 days.Freeze for Later - Freeze the sauce in a freezer-safe container for up to 2 months. Thaw in the refrigerator overnight before reheating.Reheat on Stovetop - Place a serving in a saucepan with 1 to 2 tablespoons of water or milk. Warm over low heat, stirring constantly until creamy and smooth.Reheat in Microwave - Transfer the sauce to a microwave-safe bowl. Heat in 30-second intervals, stirring between each interval, until warmed through. Add a splash of milk or cream if needed.