Peel and cut the potatoes. Then cut them into evenly-sized chunks, about an inch or so thick, and transfer them to a large stockpot full of cold water.
Boil the potatoes. Once all of your potatoes are cut, be sure that there is enough cold water in the pan so that the water line sits about 1 inch above the potatoes. Stir the garlic and 1 tablespoon sea salt into the water. Then turn the heat to high and cook until the water comes to a boil.
Reduce heat to medium-high (or whatever temperature is needed to maintain the boil) and continue cooking for about 10-12 minutes, or until a knife inserted in the middle of a potato goes in easily with almost no resistance. Carefully drain out all of the water.
Prepare your brown butter mixture. Meanwhile, as the potatoes are boiling, brown the butter. Allow the butter to melt and cook over medium heat for 3-5 minutes. Once beginning to brown slightly, add in the peeled cloves of garlic and sage. Continue to brown until you've reached an amber brown color and the sage is crispy.
Remove the sage and the garlic from the butter and set aside for garnish.
Next to the browned butter add the half and half, salt and pepper. Once the half and half is warm remove the pan from the heat and set aside.
Pan-dry the potatoes. After draining the water, immediately return the potatoes to the hot stockpot, place it back on the hot burner, and turn the heat down to low. Using two oven mitts, carefully hold the handles on the stockpot and shake it gently on the burner for about 1 minute to help cook off some of the remaining steam within the potatoes. Remove the stockpot entirely from the heat and set it on a flat, heat proof surface.
Mash the potatoes. Using your preferred kind of potato masher.
Then pour half of the melted butter mixture and the parmesan over the potatoes, and fold it in with a wooden spoon or spatula until potatoes have soaked up the liquid. Repeat with the remaining butter then add the cream cheese, folding in each pour until just combined to avoid over-mixing. (Feel free to add in more half and half to reach your desired consistency, if needed.)
Taste and season. One final time, taste the potatoes and season with extra salt if needed.
Serve warm. Then serve warm garnished with the fried sage, garlic and additional browned butter if desired.