To Make the Dashi

1. Using scissors, make around 4 x 2cm cuts into the piece of kombu. In a medium saucepan, combine the kombu, shiitake mushrooms and water. Place over medium heat and bring to a simmer. Turn off the heat, cover the pan and leave for five minutes.
2. After five minutes, remove the kombu. You can leave it to dehydrate on a cooling rack in a warm, dry area and use it again for another recipe. Turn the heat back up to medium and bring the liquid to a simmer again. Turn off the heat again, cover and leave to stew with just the shiitake mushrooms for another five minutes.
3. After five minutes have passed, combine the mushroom bouillon and the miso in a small bowl. Using a ladle, spoon a little of the dashi onto the bouillon and miso. Use a small whisk to blend everything together until smooth and creamy looking.
4. Add the miso mixture back into the saucepan of dashi and bring everything back up to a simmer. Using a slotted spoon or a spider, remove the shiitakes (which should now be fully rehydrated) and slice them finely. Set them aside for later.

To Make the Soup

1. Once the dashi is simmering, add the baby spinach and allow it to wilt for just a few seconds. Remove the cooked spinach with a slotted spoon or a spider. Carefully squeeze out any excess moisture and chop it finely. Set aside with the shiitake mushrooms.
2. Add the mirin and the tamari to the dashi. Mix to combine. Add the carrots and noodles and allow to simmer for 3-5 minutes, making sure the noodles break apart from each other.
3. While simmering, gently slice the tofu into cubes. Once the soup is ready, divide between two bowls. Top with the spinach, mushrooms, tofu, togarashi and herbs. Finish with a drizzle of sesame oil before serving.