1. Mix vegetable broth, soy sauce, honey powder, ginger, sesame oil, cornstarch, garlic, and red pepper flakes together in a small bowl.
  2. Heat vegetable oil in a wok until simmering. Add skirt steak, salt, and pepper. Cook until browned, about 5 minutes. Add stir-fry vegetables. Pour in sauce mixture. Cook until vegetables are heated through, about 5 minutes.