Grate/mince the garlic and grate the parmesan (using the small holes on a grater/microplane).

Melt butter in a skillet over medium heat. Once melted, add the minced garlic and sauté for 30 seconds, stirring often, so the garlic doesn't burn.

Add the flour, stirring constantly for about a minute until golden.To use cornstarch, create a cornstarch slurry by mixing it with a few spoonfuls of milk instead of making a roux. Then add it to the sauce after all the cream is incorporated. Note that the amount needed will differ from flour.

Slowly start incorporating the cream, little by little, stirring constantly. Then, season it with salt and pepper.

Allow the creamy garlic butter sauce to simmer and thicken (usually 2-3 minutes).

Add the parmesan, stir well, and remove the sauce from the heat.

You can now either use the sauce as is. However, when using this for creamy garlic pasta, I always dilute it with some starchy pasta water, allowing it to simmer and thicken slightly to my desired consistency.

Store: store any leftover sauce in an airtight container in the refrigerator for 4-5 days. It can become thick/gummy but will loosen up upon reheating and whisking. Freeze: allow the garlic alfredo sauce to cool and then transfer to airtight container/s (jars or containers) with a little headspace OR Ziplock bags (I like to portion mine). Store it in the freezer for up to 3 months. Upon thawing, the consistency can seem a little odd, but whisk it well when reheating, and it should sort itself out. Reheat: you can reheat the garlic cream sauce gently on the stovetop or in the microwave until piping hot (or at least 165ºF/74ºC). You may need an extra splash of cream or milk to bring it back to your desired consistency.