01 - Combine beef strips with soy sauce, cornstarch, and sesame oil in a bowl. Let stand for 10 minutes.
02 - Mix all stir fry sauce ingredients in a small bowl and set aside.
03 - Heat 1 tablespoon vegetable oil in a wok or skillet over high heat. Stir fry marinated beef for 2–3 minutes until browned but not fully cooked. Remove and set aside.
04 - Add remaining oil to the wok. Stir fry garlic, ginger, and spring onions for 30 seconds until fragrant.
05 - Add broccoli florets and red bell pepper. Stir fry for 2–3 minutes. Add 1 tablespoon water, cover, and steam for 2 minutes until vegetables are crisp-tender.
06 - Return beef to the wok. Pour in the stir fry sauce and toss for 2–3 minutes until sauce thickens and beef is cooked through.
07 - Plate immediately and garnish with additional spring onions or sesame seeds if desired.