01 - Combine thinly sliced beef with 1 tbsp soy sauce, cornstarch, and 1 tsp sesame oil in a bowl. Mix thoroughly and let marinate for 10 minutes.
02 - Cook noodles according to package instructions. Drain and rinse under cold water. Set aside.
03 - In a small bowl, whisk together soy sauce, oyster sauce, chili garlic sauce, rice vinegar, brown sugar, and toasted sesame oil until well combined.
04 - Heat 1 tbsp oil in a large wok or skillet over high heat. Stir-fry marinated beef in batches until browned, about 2 minutes. Remove from wok and set aside.
05 - Add additional oil to the wok if needed. Stir-fry garlic and ginger for 30 seconds until fragrant. Add bell pepper, carrot, and sugar snap peas, cooking for 2-3 minutes until crisp-tender.
06 - Return beef to wok. Add cooked noodles and pour sauce over. Toss well to coat and heat through for about 2 minutes.
07 - Stir in sliced spring onions. Serve immediately, garnished with sesame seeds, fresh cilantro, and additional spring onions.