Combine soy sauce and cornstarch, pour over meat. Mix to cover meat and set aside to marinate for 15 minutes.

Heat wok until flecks of water sizzle on pan surface. Add oil, swirl to coat the pan. Add garlic and ginger and quickly stir fry, about 30 seconds. Add meat and stir fry until no longer pink.

Add bell peppers and tomatoes to the meat in the wok, stir fry for 2-3 minutes. Add scallions and stir fry another minute.

Combine the oyster sauce, sugar and hot chili sesame oil until well combined. Add this sauce to the meat and vegetables in the wok. Stir to coat and bring to a boil. Turn heat down and simmer a minute or two, then serve over rice.