Steps

1. Thinly slice 30g onion.
   🕒 03:25
2. Julienne 5 shiso leaves.
   🕒 03:34
3. Finely chop 1 pack of natto with a knife. [Tip!] Chopping the natto finely helps it adhere well to the pasta.
   🕒 03:46
4. In a bowl, add 2 and 1/2 tsp soy sauce, 1 tbsp olive oil, and 5 shakes of MSG(Ajinomoto) (MSG).
   🕒 04:24
5. Add the sliced onion, finely chopped natto, natto sauce (from pack), and natto mustard (from pack), then mix well.
   🕒 04:49
6. Chill the prepared sauce in the refrigerator.
   🕒 05:13
7. Bring plenty of water to a boil in a pot, then add salt to achieve a salinity of about 1.5%.
   🕒 05:18
8. Cook 100g of 1.4mm pasta in the boiling salted water for 1 minute longer than the usual cooking time (approx. 6 minutes). [Tip!] Cook it slightly longer because it will firm up when chilled in ice water.
   🕒 05:54
9. Drain the cooked pasta in a colander, rinse it under running water to remove sliminess, and thoroughly chill it in ice water.
   🕒 07:49
10. Drain the chilled pasta in a colander, and firmly squeeze out the excess water between your hands. [Tip!] Squeeze thoroughly because any remaining moisture will dilute the sauce's flavor.
    🕒 08:07
11. Put the chilled sauce and the squeezed pasta into a bowl, and mix them well to coat. [Tip!] The stickiness of the natto will combine with the sauce, coating the pasta thoroughly.
    🕒 08:49
12. Serve on a plate, then sprinkle with shredded nori and julienned shiso leaves.
    🕒 09:09
13. If desired, sprinkle with Shichimi (Japanese chili powder).
    🕒 09:47