1Add oil to Dutch oven and place over medium high heat. Add the leeks, onions and garlic. Saute until softened. Add the chicken stock and potatoes and bring to a boil cook until potatoes are soft about 20 to 25 minutes.
2Puree with an immersion blender or food processor. Place back on stove and add the heavy cream and butter. Warm through and season with salt and pepper to taste.