Cut the tomatoes and green onion into bite-sized pieces.
Boil the somyeon noodles in boiling water, then rinse in cold water.
Heat cooking oil in a pan and sauté the green onion to release its aroma.
Add tomatoes, stir-fry for a bit, then pour in water.
Season the broth with soy sauce and sugar.
Place the cooked noodles in a bowl and pour the tomato broth over them.
Add black pepper and sesame oil to taste if desired.