Slice pork thinly, rub with koji 糀, marinate (couple of hours or overnight).
Boil water of noodles, cook them about 2-3 minutes. Drain and harden in cold water, wash them well. Place on sieve in bowl with very cold water (with ice cubes).
Heat oil, fry pork unitl done, remove from wok. Then fry bell peppers 2-3 minutes. Return pork into wok.
Mix kochijan, honey and mirin, pour into wok.
Mix water with dashi soy sauce.
Arrange somen in bowls, place fried pork with bell peppers in the center, pour in somen sauce, sprinkle with sesame. Serve.