Peel the potatoes and set aside. Rinse any excess dirt off under cold water. Dice the potatoes into approximately 1-inch cubes. Add the diced potatoes to an enameled Dutch oven and cover with water. Bring the water to a boil over medium-high heat for 30 minutes until fork tender and drain.
Once mashed, add the heavy cream, milk, and cheeses. Whip again with the handheld mixer until all is combined and smooth. Add more milk as needed until the desired consistency is met.