Cut the cabbage, onion, and green onion into bite-sized pieces as shown in the photo.
Combine the soy sauce, oyster sauce, and half of the ramyeon soup base in a small bowl to make the sauce ahead of time.
Tip.Mixing the sauce in advance lets you add it quickly once you start stir-frying, which keeps the noodles from getting mushy.
Boil the noodles in plenty of water for about 3 minutes.
While the noodles are boiling, heat some oil in a pan and stir-fry the cabbage, onion, the remaining half of the soup base, and the dried vegetable flakes for 2 to 3 minutes.
Add the boiled noodles and the prepared sauce, pour in about 1/2 cup (100 ml) of water, and stir-fry over high heat for 2 to 3 minutes.
Tip.Adding a little water helps the seasoning dissolve evenly so the sauce coats the noodles well.
Turn off the heat, add the green onion and sesame oil, and toss everything together to finish.