Peel the potatoes, removing as many of the eyes as possible with the tip of the peeler.
Submerge the potatoes in a large bowl of cold water to keep them from turning brown while you continue chopping.
Cut the potatoes into same-sized pieces so they will cook evenly, roughly 1.5-2″ cubes.
Put the cubed potatoes in a large stock pot and cover with old water. Add 1/2 tbsp salt to the water and bring the water to a boil over high heat. Once at a full boil, cover the pot and reduce heat to medium-low.
Simmer until potatoes are tender, approximately 15-20 minutes. A knife tip inserted into a potato should be able to insert and be removed cleanly and easily; if the potato clings to the knife, the potatoes need to cook longer. When the potatoes are cooked, remove from heat and drain immediately.
Return the drained potatoes to the pot and heat over medium-high heat for about a minute to cook off any excess water. Stir gently to ensure the potatoes dry out. Be sure not to let the potatoes burn/scorch.
Heat the butter and cream in a small pan on low heat until the butter is fully melted. Stir and set aside.
Use a food mill/ricer to mash the potatoes into a large bowl, and then gently stir in the butter and cream a little at a time until the desired cosistency is reached.
Season to taste, adding fresh ground black pepper and additional salt if needed. Eat immediately or refrigerate up to 24 hours.