- Stir together ginger, garlic, and two-thirds of scallions in a large bowl.
- Heat grapeseed oil in a small saucepan over high heat until oil is shimmery and hot but not smoking, about 2 minutes. Pour hot oil over scallion mixture. The scallions will sizzle, turn bright green, and wilt almost immediately. Let sit 5 minutes before stirring in remaining scallions. Stir in soy sauce, vinegar, pepper, sesame oil, and sugar; season with salt. Let sit to allow flavors to marry, 15 minutes. Taste and adjust seasonings.
- Meanwhile, cook noodles according to package directions. Drain and toss with as much or as little scallion sauce as you like.
- Divide noodles among bowls. Top with sesame seeds and serve with chili oil alongside.
Photo credit: Alex Lau/Bon Appetit
Recipe by Bon Appetit