Food & Cooking Recipes Soups, Stews & Stocks Soup Recipes Potato-Leek Soup 3.1 (82) 4 Reviews By Martha Stewart Test Kitchen Martha Stewart Test Kitchen The recipes developed by our test kitchen team have undergone a rigorous process of development and testing, ensuring that every element is optimal, from ingredient amounts to method and cooking time. This process includes triple-testing recipes to ensure they meet our high standards. The many stellar cooks and food editors who have been part of our team include Sarah Carey, Lucinda Scala Quinn, Jennifer Aaronson, Shira Bocar, Anna Kovel, Greg Lofts, Riley Wofford, Lauren Tyrell, and Lindsay Leopold. Editorial Guidelines Updated on May 16, 2017 Print Rate It Share Share Tweet Pin Email Yield: 6 This creamy potato-leek soup turns leftover mashed potatoes into a lunchtime favorite. Ingredients 1 teaspoon butter 1 medium leek, white and light-green parts only 3 ½ cups low-sodium chicken or vegetable broth 3 sprigs thyme 2 cups mashed potatoes Directions Rinse leeks well and pat dry. Halve lengthwise and chop. In a large saucepan, melt butter over medium high. Add 1 cup chopped leeks and cook, stirring, until softened, 3 minutes. Add broth, 1/2 cup water, and thyme and bring to a boil. Reduce to a simmer and whisk in mashed potatoes. Simmer until warmed through; season with coarse salt and ground pepper. Rate it Print