First, add butter to a pot/saucepan over medium heat. Next, add minced garlic and sauté for 1 minute. After that, heat heavy cream and half and half over medium-high heat for 4 to 5 minutes. Once the mixture forms bubbles, add parmesan cheese and Asiago cheese and continue to whisk. Now, add salt and black pepper and mix. The sauce might still be runny at this point, but it will thicken as it cools down.