To tenderize the beef strips so they’re not chewy, combine the baking soda with the beef and mix well. Add 1 tablespoon of water if the mixture feels too dry. Let it sit for 30 minutes to “velvet” the beef. In the video below we discuss how the texture of the beef will change.
After 30 minutes, rinse the beef thoroughly several times, then drain and squeeze out excess water.
Season the beef with soy sauce, brown sugar, Worcestershire sauce, grated ginger, Mirin, water, salt, black pepper, garlic, and jerk marinade (if using). Cover and marinate in the fridge for at least 2 hours or overnight for best flavor.
Heat vegetable oil in a wok over medium heat. Add the marinated beef (reserve the marinade) and stir-fry for about 5 minutes until the beef is browned and most of the liquid has evaporated.
Add the red, orange, and green bell peppers along with the sliced onion. Stir and cook for 2–3 minutes, allowing the vegetables to stay slightly crisp.
In a small bowl, whisk the cornstarch into the reserved marinade, then pour into the wok. Stir continuously for 3 minutes until the sauce thickens and coats the beef.
Add the chopped scallions, taste, and adjust salt if needed. Turn off the heat after 1 minute, then sprinkle with sesame seeds.
Serve hot with coconut rice or steamed jasmine rice.
