Boil the somyeon noodles and rinse them in cold water.
Drain the oil from the canned tuna using a strainer.
In a bowl, mix soy sauce, water, minced garlic, sesame oil, and sugar to make the sauce.
Place the tuna and sauce on top of the noodles, then mix well.
Sprinkle chopped green onions and crushed seaweed on top to taste.