Recipes Buttermilk Mashed Potatoes Be the first to rate & review! What pasta is to Italy, potatoes are to Belgium. This version of mashed potatoes mixed with other vegetables is called stoemp and is deeply rooted in the tradition of peasant cooking.Plus: More Vegetable Recipes and Tips By Ruth Van Waerebeek-Gonzalez Updated on December 22, 2015 Print Rate It Share Share Tweet Pin Email Yield: 6 Ingredients 2 pounds baking potatoes, peeled and cut into 1/2-inch dice 1 firm medium celery root (about 1 pound), peeled and cut into 1/2-inch dice Salt 2 tablespoons unsalted butter 4 small leeks, white and light green parts, sliced crosswise 1/2 inch thick 1/2 cup heavy cream Freshly ground pepper 1 cup buttermilk 1/4 teaspoon freshly grated nutmeg Directions In a large saucepan, cover the potatoes and celery root with water, add a pinch of salt and bring to a boil. Simmer over moderate heat until the vegetables are tender, 35 to 40 minutes. Drain the vegetables and return them to the pan. Meanwhile, melt the butter in a small saucepan. Add the leeks, cover and cook over moderate heat for 5 minutes. Add the cream, season with salt and pepper and simmer, uncovered, until the leeks are tender, about 7 minutes. In another small saucepan, gently heat the buttermilk; do not boil or it will curdle. Coarsely mash the potatoes and celery root. Stir in the hot buttermilk and then the creamed leeks. Season with salt, pepper and nutmeg and serve. Rate it Print