Melt the butter in a medium saucepan set over medium heat. (6 tbsp unsalted butter)
Add the garlic and cook until lightly browned and fragrant. (1 clove garlic)
Remove the pan from the heat and let it cool for 3-5 minutes.
Pour in the room temperature heavy cream. Whisk until combined. (1½ cups heavy cream)
Once the cream is fully combined, place the pan back on the stove over low heat. Do not let the sauce come to a boil – keep it over low heat.
Add the grated cheese and continually whisk the sauce together until the cheese is completely melted and evenly combined. (Go slow, a little bit at a time) (6.4 oz. freshly grated Parmesan cheese)
Taste and season with salt, pepper, and thyme. (kosher salt, ground black pepper, minced fresh thyme)