Add the potatoes to a large pot of generously salted water and bring to a boil. Turn the heat down to a simmer and cook the potatoes until fork tender, approximately 20-25 minutes.
Drain the potatoes and transfer to a large mixing bowl. Using a hand mixer, beat the potatoes, sour cream and milk until fluffy. Stir in the chives. Season with salt and pepper, to taste. Serve immediately.