Steps

1. Remove the tough stems from the shiitake mushrooms.
   🕒 02:07
2. Peel off one outer layer of the leek and slice it diagonally into approximately 1cm thick pieces.
   🕒 02:19
3. Thinly slice the ginger.
   🕒 02:43
4. Make vertical cuts into the skin of the mackerel. This technique ensures even simmering and flavor penetration.
   🕒 02:58
5. Bring water to a boil in a pot and blanch the mackerel for about 10 seconds. This 'shimo-furi' process removes impurities, sliminess, and any odor-causing elements.
   🕒 03:59
6. Immediately transfer the blanched mackerel to an ice bath and gently remove any floating impurities.
   🕒 04:23
7. Thoroughly pat the mackerel dry. Carefully removing moisture is crucial to prevent any fishy odor.
   🕒 05:10
8. In a frying pan, combine [A] Water 400cc, [A] Cooking Sake (Rice Wine) 200cc, [A] Soy Sauce 2 tbsp, [A] Mirin (Sweet Rice Wine) 4 tbsp, and [A] Sugar 4 tbsp. Stir until the sugar is mostly dissolved.
   🕒 05:43
9. Heat the pan and bring the simmering liquid to a boil. Boiling the liquid beforehand helps to reduce any fishy smell.
   🕒 06:02
10. Add the prepared mackerel to the boiling liquid, ensuring they do not overlap.
    🕒 06:47
11. Cover the mackerel with aluminum foil to keep the simmering liquid distributed over the fish. Simmer over medium heat for 10 minutes. Avoid moving or flipping the fish once it's in the pan to prevent it from breaking apart. Overcooking can toughen the fish; the aim is a tender result with a rich sauce.
    🕒 07:24
12. In a separate bowl, place Miso 6 tbsp and mix with a small amount of the simmering liquid until dissolved. Adding miso towards the end helps preserve its aroma.
    🕒 08:18
13. Add the dissolved miso to the frying pan. Also, add the shiitake mushrooms, leek, and ginger into the empty spaces.
    🕒 08:39
14. Cover again with aluminum foil and continue to simmer over medium heat for another 3 minutes.
    🕒 09:33
15. Check the consistency of the simmering liquid. Once the fish is fully cooked, arrange the mackerel and vegetables on a serving plate.
    🕒 10:55
16. Generously ladle the simmering sauce over the mackerel and vegetables. Your dish is complete!
    🕒 11:51