Soak the kombu in the water for about 30 minutes.

Add the bonito flakes to the saucepan of kombu broth.

Heat over medium heat.

When it comes to a boil, skim off the foam.

Reduce the heat and let steep for 5 minutes.

Turn off the heat and strain through a strainer lined with paper towels.

Press the bonito flakes firmly to extract a rich dashi.

Cut the carrot into 5 rounds, 3 mm thick, then cut them into maple leaf shapes.

Cut the leek into 6 pieces, 4 cm long, then slice the rest diagonally into 7 to 8 mm slices. Reserve the diagonal slices for the udon.

Remove the shiitake stems and score a cross into the caps.

Trim the base of the shimeji and separate them into small clusters.

Cut the seri into 7 cm lengths.

Cut the silken tofu into 4 pieces.

Cut the mochi in half.

Thinly peel the yuzu, remove the white pith, cut the zest into thin strips, then finely chop.

Grate the daikon.

Sprinkle the oysters with about 1 teaspoon of salt, then toss gently and briefly.

Rinse under running water and drain in a strainer.

Lower the strainer into boiling water and gently stir the oysters with chopsticks.

After about 10 seconds, as soon as they plump up, remove them immediately.

Salt the salmon and cod on both sides, press lightly, and let rest for 20 minutes until the surface is moist.

Rinse thoroughly with water to remove any fishy smell, then pat dry with paper towels.

Slice the salmon diagonally into 4 pieces, and do the same with the cod.

Grate the ginger and drizzle its juice over the fish to coat.

Pour about 1 cm of oil into a frying pan and heat to 170°C.

Fry the mochi, turning them until golden on all sides.

When they puff up slightly, remove and drain.

Coat the salmon in potato starch and tap off the excess.

Fry at 170°C, turning the pieces, then drain on paper towels once golden.

Fry the starch-coated cod in the same way, turning the pieces, then drain.

Pour the dashi into a donabe (earthenware pot) and heat.

When it comes to a boil, add the sake, mirin, salt, and light soy sauce, then stir.

Add the carrot, leek pieces, shiitake, and shimeji.

Cook for 1 to 2 minutes.

Add the grated daikon, tofu, fried salmon and cod, mochi, and oysters.

When it returns to a boil, skim off the foam.

Finally, add the seri.

Do not overcook the grated daikon, as it quickly loses its goodness when heated.

Serve in individual bowls.

Add the udon to the remaining broth.

Top up with a little dashi if the broth has reduced too much.

Adjust the seasoning with a little light soy sauce and mirin.

Add the reserved diagonal leek slices and separate the noodles with chopsticks.

Serve with the condiments: yuzu kosho, shichimi, and yuzu zest.