To start, peel and cut the potatoes. Place a pot of water on the stove and bring to a boil. Add about 2 teaspoons of salt to the water.
Add the potatoes then lower the heat to a simmer, cover the pot. Allow them to boil about 20 minutes. Meanwhile, proceed to the next step.
In a pot on low heat add the buttermilk and butter. Allow them to warm up. The butter should melt but the mix should not steam. Only a heat low enough to heat the ingredients a little.
Now, once the potatoes are fork tender drain the water. Then, add the potatoes to a bowl. Pour the heated buttermilk and butter in the potatoes. Next, using a hand mixer mash the potatoes a little then mix them until smooth and whipped.
Lastly, add salt and pepper to taste before serving.