Your leftover Thanksgiving mashed potatoes become a creamy vegetable soup.
In saucepan, heat oil over medium-high. Add leeks and onion; season with salt and pepper. Cook, stirring occasionally, until vegetables brown and soften, about 10 minutes. Transfer to blender. Add stock and potatoes; blend until smooth, about 1 minute. Return soup to saucepan. Stir in cream. Heat soup over medium-low until hot. Garnish soup with crème fraîche and chives. Drizzle with EVOO.