Prepare the Potatoes: Peel the potatoes and cut them into roughly 2-inch chunks. Place them in a large pot and cover with cold water by about an inch. Add a generous pinch of salt to the water.

Boil Until Tender: Bring the pot to a boil over medium-high heat, then reduce the heat to maintain a gentle boil. Cook for about 15 minutes, or until the potatoes are very tender when pierced with a fork.

Drain: Drain the potatoes well and return them to the warm pot.

Mash the Potatoes: Add the butter, milk, and cream cheese to the pot. Mash the potatoes using a potato masher or a potato ricer until mostly smooth and creamy.

Add the Garlic and Cheese: Stir in the minced garlic, shredded cheddar, Parmesan, salt, and pepper. Continue mashing or stirring until the cheeses are fully melted and everything is well combined. Add a splash of more milk if you prefer a softer, creamier texture.

Taste and Adjust: Taste and adjust the seasoning with more salt and pepper if needed. For an extra-rich flavor, top with a little extra cheddar or a pat of butter before serving.