In a medium saucepan, cover the potatoes with 2 inches of water. Bring to a boil over high and cook until tender, 12 to 14 minutes. Meanwhile, in a small saucepan, heat the milk, EVOO, butter, 1/2 tsp. salt and 1/4 tsp. pepper over medium until the milk is warm and the butter melts, about 2 minutes. Drain the potatoes; return to the medium saucepan. Pour the milk mixture over the potatoes; mash with a potato masher until mostly smooth. Stir in the chives.