Combine all the ingredients for the miso paste together in a blender or food processor until a smooth, thick paste forms. You'll only need half for this recipe so you can refrigerate or freeze the extra for later use.

Preheat oven to 375 degrees F (190C) and line a baking tray with parchment. Use paper towels or a tofu press to get out as much liquid from the tofu as you can. Cut into cubes and gently toss in a large bowl with the sesame oil. Place on tray and bake for 20 - 25 minutes or until browned on the edges. Once the tofu has browned, remove pan from oven and allow to cool.

In a non-stick skillet add the mushrooms and cook for 2 - 3 minutes until mostly cooked. Add about a tablespoon of miso paste stir until warmed. Add the stock and lime juice then bring to a simmer. Take about 1/2 cup of the miso paste in a very fine sieve. Lower the sieve half-way into the simmering soup and use a spoon to slowly dissolve the paste into the soup. Throw away the pieces left in the sieve and simmer the soup for another 5 minutes. Add salt to taste (you can also use soy sauce or tamari).

Cook the ramen noodles according to package instructions and drain well. Divide the noodles into four large bowl and ladle the soup on top (you'll probably have extra). Top each bowl with the tofu, scallions, and sesame oil. Serve with additional limes.