Horseradish and Sour Cream Mashed Potatoes

(recipe by Tyler Florence)
4 pounds russet potatoes, peeled, and cut into large chunks
2 bay leaves
Kosher salt and black pepper
2 cups sour cream
1 stick unsalted butter
3 tablespoons horseradish
chopped fresh chives

Put the potatoes in a large pot, add the bay leaves, salt, pepper, and cover with water.  Bring to a boil over medium-high heat and cook until the potatoes are tender, about 20 minutes.  Remove the bay leaves and drain the water from the potatoes, reserving about 2 tablespoons.  Smash the potatoes in a large mixing bowl.  Add the sour cream, butter, cooking water, and horseradish.  Season well with salt and pepper and garnish with the chopped chives.