Peel the potatoes and dice them into equal-sized pieces, about 1 inch thick.
Place them in a large pot and cover with cold water, about 1 inch above the potatoes.
Add 4 garlic cloves and about 2 teaspoons of salt to the water.
Bring the pot to a boil over high heat, then reduce the heat to medium and simmer until the potatoes are fork-tender, about 15 minutes.
Drain the water and return the potatoes and garlic to the pot to allow any excess water to evaporate from the residual heat. Then transfer them to a large mixing bowl.
While the potatoes are still hot, mash them along with the garlic until smooth and fluffy, using a potato masher, stand mixer, or hand beater.
Gradually add the melted unsalted butter and mix well.
Next, add the warm heavy cream, cream cheese, salt to taste, and grated parmesan. Mix until smooth and creamy.
Taste and adjust the salt according to your preference. If you prefer thicker mashed potatoes, use less heavy cream; for a creamier texture, add more heavy cream.
Serve warm, garnished with chopped parsley or chives.