Preparation
For the broth: combine soy sauce, kombu seaweed and katsuobushi with the dashi. Add more soy sauce, sake and sugar.
For the dressing: boil the fava beans, crisp the bacon in a pan. Then, cut the tuna into thin strips and marinate it in the soy sauce with sake and sugar. Cut the takuan into very small cubes and, finally, the spring onion into thin strips.
For the somen: bring the water to a boil and let the somen boil for 3 to 4 minutes. Then, drain them and rinse them in cold water to stop the cooking.
To serve: place the somen on a plate, add the fava beans, bacon and takuan. Add the yuzu powder, spring onion, and a drizzle of olive oil. Finally, add the tuna and with the wasabi the broth.
Source: Maguro Somen recipe, the award-winning Japanese noodles with tuna by master Haruo Ichikawa | Cook (corriere.it)