Start by soaking the shiitake mushrooms in warm water for about 30 minutes. Once soaked, transfer into a saucepan, cover with water and add 1 tablespoon of less salty soy sauce. Bring to boil and let simmer for 10-15 minutes or until the mushrooms are tender. Drain and set aside.
Heat the olive oil in a frying pan, add the chicken and cook for 5-10 minutes breaking it into smaller pieces and turning it as you go. Add the ginger and the shallots and cook for a further few minutes.
In a bowl, mix the miso with 1 tablespoon of less salty soy sauce, cooking sake and miring and add water to form a smooth but watery paste. Add the miso paste into the saucepan and stir through. Add the brown rice vinegar, a pinch of shichimi togarashi, all mushrooms and wakame, mix well to combine and let simmer for 10 minutes. Season with a tiny drizzle of sesame oil and a couple of tablespoons of toasted sesame seeds, stir well. Cover, turn off the heat and let sit until the noodles are cooked. Cook the noodles according to packet instructions (I cooked mine in boiling water for about 3 minutes). Serve the noodles with the sauce and sprinkle with some extra sesame seeds.