01 - Combine beef, soy sauce, sesame oil, and cornstarch in a bowl and let stand for 10 minutes to marinate.
02 - Cook noodles according to package directions, drain, rinse under cold water, and set aside.
03 - Whisk together soy sauce, oyster sauce, hoisin sauce, rice vinegar, sriracha, brown sugar, and water until smooth.
04 - Heat 1 tablespoon vegetable oil in a wok or large skillet over high heat. Stir-fry beef for 2 to 3 minutes until just cooked. Remove and set aside.
05 - Add remaining vegetable oil to wok. Stir-fry bell peppers, carrot, and sugar snap peas for 2 to 3 minutes until crisp-tender.
06 - Incorporate garlic, ginger, and chilies; stir-fry for 1 minute until fragrant.
07 - Return beef to wok, add cooked noodles and sauce. Toss continuously for 2 to 3 minutes until heated through and evenly coated.
08 - Sprinkle with sliced spring onions and serve immediately.