Ingredients:

• 1 pack of fermented soybeans (納豆, nattō)
• 1 small fried tofu (揚げ豆腐, agedōfu)
• 150 g of Sawamo dashi (出汁, dashi, Japanese broth made from kombu seaweed and dried bonito)
• 1/2 tofu (豆腐, tōfu, preferably firm)
• 1/2 carrot (人参, ninjin)
• 80 g of salted fern (ゼンマイ, zenmai, edible fern)
• 1 leek (長ねぎ, nagane-gi)
• 50 g of Takana (高菜, takana, pickled mustard leaves)
• 70 g of miso (味噌, miso)
• 5-6 dried sardines (煮干し, niboshi, dried sardines used for broth)
• 800 cc of water (水, mizu)

Preparation:
Prepare the ingredients:

1. Remove the excess salt from the Sawamo dashi, salted fern (zenmai), and Takana (takana).
2. Place the fermented soybeans (nattō) in a clay mortar and mash them until sticky, optionally adding Japanese radish (daikon) to soften the smell.

Prepare the broth:
3. In a pot, prepare a broth using dried sardines (niboshi). The broth should be slightly darker than a classic miso soup.

Prepare the vegetables and tofu:
4. Slice the carrot (ninjin) into thin rounds.
5. Cut the fried tofu (agedōfu) into small, oil-free portions.
6. Cut the fern (zenmai) and Takana (takana) into pieces about 2 cm long.
7. Dice the tofu (tōfu) and finely chop the leek (nagane-gi).

Cook the vegetables and tofu:
8. In a large pot, add the carrots (ninjin), Sawamo dashi (dashi), and fern (zenmai). Cook until the vegetables are tender.
9. Add the tofu (tōfu) and miso (miso). Adjust the flavor to make it slightly stronger than a typical miso soup.

Add the fermented soybeans:
10. Add the mashed fermented soybeans (nattō) to the soup. Stir well and let it simmer for a few minutes.

Finish the soup:
11. Bring the soup to a boil, then add the Takana (takana) and leek (nagane-gi). Adjust the quantities to your taste.

Serve:
12. Let the soup simmer for a few more minutes and serve it hot. This comforting dish is perfect for warming up on cold days.