Bring a large pot of salted water to a rolling boil and cook the noodles according to package directions until just under al dente (about 1 minute less than package time). Reserve 1/3 cup of the cooking water, then drain and return the noodles to the hot pot off the heat.

In a small saucepan over low heat, warm the neutral oil and toasted sesame oil. Add the minced garlic and sweat gently for 30–45 seconds until fragrant but not browned. Stir in soy sauce, rice vinegar, brown sugar, and crushed red pepper. Bring to a very gentle simmer for 20–30 seconds, then remove from heat and taste to adjust seasoning.

Pour the warm sauce over the hot drained noodles. Add 1 tablespoon of sliced scallions and the toasted sesame seeds, then toss vigorously with tongs for 30–60 seconds until the noodles are evenly coated and glossy. If the noodles seem dry, add reserved cooking water 1 tablespoon at a time until silky.

Transfer to bowls, garnish with remaining scallions, extra sesame seeds, and optional cilantro or protein, and serve immediately.