Start by making the dashi. In a pan put the water and just before it starts boiling, add the kombu seaweed, the dehydrated mushrooms and bonito flakes.
Boil for 5 min and discard the kombu seaweed and bonito flakes.
Lower the heat and add the miso and soy sauce and cook for 2 or 3 min.
In a separate pot, cook the noodles for about 5 to 6 min or according to the package instructions.
Saute the shimeji mushrooms and pak choi in a pan with sesame oil for 3 to 4 min or until the pak choi is al dente.
Cook the egg for 5 to 6 min in a pan of boiling water.
Assemble your ramen. Divide the noodles between 2 bowls, then place the pak choi and shimeji mushrooms.
Peel the egg carefully because this egg gets very soft and the yolk is undercooked, break it in half and put each half in each bowl.
Drizzle with the dashi and finally sprinkle with the sesame seeds.