Boil potatoes off in a large pot of salted water until tender. Drain the water and place potatoes back in pan.
In a large saucepan, heat heavy cream, butter and garlic to a light simmer. Once cream starts to simmer, turn off the heat and add to the potatoes. Mash together. Fold in cheese, peppercorns and salt, to taste. Garnish with chopped chives.