Food & Cooking Recipes Soups, Stews & Stocks Soup Recipes Cold Soba Broth 4.0 (3) Close Servings: 4 This cold soba broth recipe, courtesy of chef Takashi Yagihashi (Takashi's Noodles), is used to make Natto Soba.Reprinted with permission from Takashi's Noodles by Takashi Yagihashi with Harris Salat, copyright 2009. Published by Ten Speed Press. Photo credit: Tyllie Barbosa 2009 Directions In a large pot, bring dashi, soy sauce, and mirin to a boil over high heat. Immediately reduce heat to a simmer and add katsuobushi; simmer for 2 minutes. Remove from heat and let stand for 3 minutes. Prepare an ice-water bath. Place a fine mesh strainer over a bowl. Strain dashi mixture into bowl and set bowl in ice-water bath until cool.