Recipes Soups Vegetable Soups Potato Soups Creamy Mashed Potato Soup with Dashi 4.0 (1) 1 Review Dashi and soy sauce add umami to buttery leftover mashed potatoes in this cozy soup from chef Shota Nakajima. As a kid, whenever he was hungry, he’d grab anything left over from the previous meal to make soup or fried rice. “I grew up in a Japanese family, and I was taught to never waste anything,” Nakajima says. This soup is his riff on a recipe from his mother. Add milk for a creamier texture, or more dashi for a thinner consistency. Substitute any mashed vegetable you have on hand, such a cauliflower or sweet potato, but be sure to finish the soup with generous pats of melting butter and an extra drizzle of soy. By Shota Nakajima Updated on August 2, 2023 Tested by Food & Wine Test Kitchen Tested by Food & Wine Test Kitchen Recipes published by Food & Wine are rigorously tested by the culinary professionals at the Dotdash Meredith Food Studios in order to empower home cooks to enjoy being in the kitchen and preparing meals they will love. Our expert culinary team tests and retests each recipe using equipment and ingredients found in home kitchens to ensure that every recipe is delicious and works for cooks at home every single time. Meet the Food & Wine Test Kitchen Save Rate PRINT Share Close Photo: Photo by Victor Protasio / Food Styling by Torie Cox / Prop Styling by Claire Spollen Active Time: 20 mins Total Time: 4 hrs Yield: 4 Cook Mode (Keep screen awake) Ingredients 1 medium-size yellow onion, finely chopped 2 large celery stalks, finely chopped 2 1/2 to 3 1/2 cups dashi or chicken stock 3 cups leftover mashed potatoes 1/4 cup whole milk (optional) 1/2 teaspoon kosher salt, or to taste 1/4 teaspoon black pepper, or to taste Unsalted butter and soy sauce, for serving Chopped mitsuba or celery leaves, for garnish Directions Combine onion, celery, and 2 1/2 cups dashi in a small Dutch oven. Bring to a boil over medium-high. Reduce heat to medium-low, and simmer, uncovered, stirring occasionally, until vegetables are tender, 35 to 40 minutes. Add leftover mashed potatoes to dashi mixture, and whisk until well combined. Stir in milk, if desired, for a creamier texture. Stir in remaining 1 cup dashi, 1/4 cup at a time, to thin soup to desired consistency. Cook over medium-low, stirring occasionally, until warm, 4 to 6 minutes. Season with salt and pepper. Top servings with butter and drizzle with soy sauce. Garnish with mitsuba or celery leaves. Make Ahead Soup can be prepared up to 3 days in advance and stored in an airtight container in refrigerator. Reheat over low, stirring often to prevent simmering. Suggested Pairing Aromatic dry Riesling. Originally appeared: November 2020 Rate It Print