Food Forum
Vol. 28 No. 2  July 2014




This soup is a flavorful combination of various soybean products, including natto, fermented soybeans. Here, the sticky texture of the natto is reduced a bit when sautéed; despite its aroma during preparation, neither its smell nor taste overpowers the soup, making this an appealing dish even for those who are not fans of natto.


Serves 3-4

127 kcal  Protein 8.5 g  Fat 7.8 g (per person)

  • 8 green onions, 40 g / 1.5 oz. total
  • 2 t vegetable oil
  • 2 packs natto, each 40 g / 1.5 oz.; set aside Japanese mustard packets, if included
  • 1 t mustard (preferably Dijon), or more to taste
  • 600 ml (2 1/2 C) bouillon*
  • 1 stem fresh thyme, or 2 pinches powdered thyme
  • 1 bay leaf
  • 150 g (1/3 lb.) tofu, firm or soft, drained, cut into 1 cm (1/2 in.) cubes
  • 200 ml (5/6 C) soy milk
  • 1 + 1/2 t Kikkoman Soy Sauce, or more to taste
  • Black pepper to taste
Optional garnish
  • Chopped green onion leaves
  • Chopped parsley
  • 1/2 piece abura-age**, deep-fried tofu
  • Kikkoman Soy Sauce


  1. Separate the hollow green leaves from the solid part of the onion. Finely chop the solid part for use in the soup; then cut up a few of the hollow green leaves to set aside for optional garnish.
  2. Heat vegetable oil in a heavy-bottomed pan. Add natto and sauté over low heat, stirring lightly to prevent burning. Add the chopped onion and sauté until soft.
  3. Stir in pre-packaged Japanese mustard from the natto along with the mustard.
  4. Add the bouillon to the sautéed natto. Wrap thyme and bay leaf together in cheesecloth or pack into a bundle, and add to the pot. Bring to a boil; lower heat and simmer for 2-3 minutes.
  5. Add the diced tofu; after it rises to the surface, add the soy milk and 1 t soy sauce, then heat to just under the boiling point.
  6. Taste and depending on preference, add another 1/2 t soy sauce or more and sprinkle with black pepper.
  7. Serve in individual bowls garnished with chopped green onion leaves, parsley and/or abura-age, depending on preference. Serve hot.

* Either meat- or vegetable-based bouillon cubes or powder may be used. Use about 3/4 the amount of bouillon suggested in directions for a mild soup base.
** Preheat a non-stick frying pan. Over low heat, lightly brown both sides of the abura-age, pressing it down. Remove pan from heat, brush tofu with soy sauce. Cut in half and slice into 5 mm (1/4 in.) strips.

Recipe by Michiko Yamamoto

1 C (U.S. cup) = approx. 240 ml; 1 T = 15 ml; 1 t = 5 ml

This recipe was inspired by “The Japanese Table” feature article “Washoku: Balanced and Healthy” included in this issue.