Drain the potatoes and place back in the saucepan. Cover with a dish towel and allow the steam to evaporate any excess water for 5 minutes. Remove the towel, squeeze in the roasted garlic, and in the infused milk mixture. Press through a ricer or mash with a potato masher until creamy and smooth. Add the cream cheese/mascarpone, parmesan cheese, ½ teaspoon salt, a pinch of black pepper, or more to taste, and stir to combine. Cover to keep warm.