1. In a large pot, heat the oil over medium heat until it is lightly bubbling, about five to eight minutes.
2. In the meantime, add the garlic, scallions, chili flakes, sesame seeds, and sugar into a bowl. Carefully pour the hot oil over the garlic mixture. It will sizzle. Allow it to cool for a few minutes. Add your vinegar, soy sauce, and sesame oil and give it a good mix.
3. Toss with your noodles until coated.
4. Top with cucumber, sesame seeds, and scallions.