Peel the potatoes and cut them into like sized chunks. Place them in a pot of salted water and boil until fork tender, about 15-18 minutes.
While the potatoes are cooking, simmer the milk, butter, and garlic together in a small saucepan, making sure to NOT let it boil. Side Note: This is an important step because it will poach the garlic which will make the garlic flavor more subtle instead of it being raw and overpowering the potatoes.
Once the potatoes are fork tender. Drain them in a strainer well. Place the potatoes back in the pot and add the warmed milk and garlic mixture then mash using a hand masher. Add the Parmesan and season with sea salt and freshly cracked pepper, to taste; Continue to mash until well combined. Taste and re-season if needed. Serve immediately. Enjoy.