Wash and peel the potatoes, then cut them into large chunks and place in a large pot.Cover the potatoes with cold water by 1 to 2 inches and add a generous amount of salt. (You want the water to taste like the ocean.)
Place the pot on the stove over high heat.Once the water boils, reduce the heat and simmer until the potatoes can easily be pierced with a knife, about 20 minutes.
Drain in a colander and let the potatoes rest in the sink while you prepare the butter and cream.
Combine the butter and cream in the pot you cooked the potatoes in. Cook over low heat, stirring, until the butter has melted and the cream is hot.Turn off the heat and add the drained potatoes. Using a potato masher, mash until the potatoes are fluffy and creamy. Season with salt and pepper to taste.
