01 - Combine sliced beef with 1 tablespoon soy sauce, 1 teaspoon cornstarch, and 1 teaspoon sesame oil in a bowl. Mix thoroughly and let marinate for 10 minutes.
02 - In a separate bowl, whisk together soy sauce, oyster sauce, hoisin sauce, rice vinegar, brown sugar, minced garlic, grated ginger, cornstarch, and water until smooth. Set aside.
03 - Heat 1 tablespoon vegetable oil in a large wok or skillet over high heat. Add marinated beef in a single layer and stir-fry for 2 to 3 minutes until just browned. Remove beef and set aside.
04 - Add remaining 1 tablespoon vegetable oil to the wok. Stir-fry sliced carrots for 2 minutes, then add snow peas and continue cooking for another 2 minutes until vegetables are crisp-tender.
05 - Return beef to the wok and pour in prepared sauce. Stir frequently for 1 to 2 minutes until the sauce thickens and evenly coats beef and vegetables.
06 - Remove from heat, garnish with sliced spring onions if desired, and serve immediately over steamed rice or noodles.