Clean the green onions thoroughly and julienne them into strips about 5–7 cm long.
Soak the julienned green onions in cold water to remove the sharp taste, then drain the water.
In a bowl, mix green onions, gochugaru (Korean red pepper flakes), sesame oil, vinegar, sugar, soy sauce, and sesame seeds.
If desired, add extra chili peppers or minced garlic and mix well.
Place the finished green onion salad on a plate to serve.