Bring a pot of water to a boil. I usually do this in a pan wide enough to fit the somen sideways but also deep enough so the water won't spill.
In a separate pan, add the 70 grams canned tuna in oil, 50 grams carrots, and 50 grams onions and stir-fry until the onions become translucent.
Add the 75 grams cabbage and continue to stir-fry until the cabbage has wilted.
When the pot with the water is at a full boil, add the somen noodles and submerge them as quickly as possible. Cook the noodles for about half the time specified on the package.
Transfer the somen straight into the pan with the rest of the chanpuru ingredients with tongs, and add in the 50 grams garlic chives and half of the 4 grams katsuobushi.
Stir-fry the somen with the vegetables and season with ¼ teaspoon salt and White pepper to taste. If the noodles start to stick together, add some Vegetable oil as needed.
Plate the somen chanpuru and sprinkle the remaining katsuobushi on top.