Peel, quarter, and rinse the potatoes. Put the potatoes in a pot, add the salt, and cover with cold water.
Bring to a boil, then lower the heat and cook until tender but still firm, about 15-20 minutes. Drain them well.
Heat the milk and butter in a small saucepan. Using a potato masher or electric beater, mash the potatoes with oil and sour cream. Add freshly ground black pepper. Slowly blend milk mixture into potatoes until smooth and silky creamy.
To serve, garnish with chives.
Notes
Always add warm milk to the potatoes because the cold liquid will not absorb into the hot potatoes very well.
A pinch of nutmeg adds a wonderful aroma to the dish.