In a small bowl, whisk together soy sauce, honey, rice vinegar, sesame oil, and cornstarch (if using). Set aside.
Heat 1 tablespoon of vegetable oil in a large pan or wok over medium-high heat. Once hot, add the sliced beef in a single layer. Stir-fry for about 2-3 minutes until browned and just cooked through. Remove beef from the pan and set aside.
In the same pan, add the remaining tablespoon of oil. Add minced garlic and ginger, stir-frying for about 30 seconds until fragrant.
Toss in the broccoli florets, bell pepper slices, and julienned carrots. Stir-fry for 4-5 minutes until the vegetables are tender-crisp.
Return the cooked beef to the pan along with the sauce you prepared earlier. Stir well to coat all ingredients in the sauce. Cook for an additional 2-3 minutes until everything is heated through and slightly thickened.
Stir in the chopped green onions. Remove from heat.
Notes
Serve over steamed jasmine rice or quinoa, and garnish with sesame seeds and extra green onions for a pop of color.