Crispy sourdough topped with sticky, savory natto makes for a surprisingly satisfying breakfast that bridges Japanese tradition and modern convenience.

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Servings

2

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Prep

5 min

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Cook

4 min

Natto toast is one of those rare dishes where something ancient meets something effortless. Natto — fermented soybeans with a sticky, stringy texture and a deep umami flavour — might seem like an unusual toast topping, but once you try it, the combination is genuinely compelling. The crunch of toasted sourdough contrasts beautifully with the soft, pungent natto, while a few simple toppings — mustard, soy sauce, and sliced green onion — tie everything together. This recipe keeps things approachable whether you are a natto veteran or trying it for the very first time.

Ingredients

  • 2 thick slices sourdough bread (about 120 g total)
  • 1 pack natto (50 g), typically sold in individual styrofoam or paper packs
  • 1 tsp soy sauce
  • 1 tsp Japanese mustard (karashi) or Dijon mustard
  • 1 tsp sesame oil
  • 1 green onion (scallion), thinly sliced
  • ½ tsp toasted sesame seeds
  • 1 soft-boiled or fried egg (optional)
  • A few drops of sriracha or chili flakes (optional, for heat)

Instructions

  1. Toast the sourdough slices in a toaster or under a grill until golden and crisp, about 3–4 minutes.
  2. Open the natto pack. Add the included sauce packet (if any), the soy sauce, mustard, and sesame oil directly into the natto container or a small bowl.
  3. Stir the natto vigorously with chopsticks or a fork for about 30–60 seconds until it becomes very sticky and stringy. This develops the flavour and texture.
  4. Spoon the natto mixture evenly over the toasted bread slices.
  5. Top with sliced green onion and toasted sesame seeds.
  6. If using, place a soft-boiled or fried egg on top.
  7. Add a few drops of sriracha or a pinch of chili flakes if you like heat. Serve immediately.

Tips

  • Stir well: The more vigorously you stir natto before topping, the richer and more cohesive the flavour becomes — don't skip this step.
  • Bread choice: Sourdough works best for its tang and structure, but rye or whole-grain toast are excellent alternatives.
  • Storage: Natto packs keep well in the fridge for up to a week and can be frozen for up to a month. Thaw overnight in the fridge before use.
  • Toppings to try: Thinly sliced avocado, a drizzle of ponzu, pickled ginger, or shredded nori all pair beautifully with natto on toast.

Natto has been a staple of Japanese cuisine — particularly in the Kantō region around Tokyo — for over a thousand years. Traditionally eaten as a breakfast food alongside rice, miso soup, and pickles, it is made by fermenting soybeans with the bacterium Bacillus subtilis var. natto, giving it its signature sticky texture and bold, complex aroma. Serving natto on toast is a modern adaptation that has become popular in Japan as Western-style breakfasts have woven into everyday life.

Nutrition of key ingredients — per 100 g of each ingredient separately (not per serving), source USDA

IngredientkJ / kcal
natto211
sourdough bread0
soy sauce60
green onions0
sesame oil884

Medical Disclaimer: This article is for educational purposes only and does not constitute medical advice. Always consult a qualified healthcare professional before starting any supplement regimen or making changes to your diet, especially if you have a medical condition or take medications.