In a medium bowl, combine the sliced flank steak, soy sauce, and 1 tablespoon of sesame oil. Let it marinate for at least 15 minutes.
In a large skillet or wok, heat the remaining tablespoon of sesame oil over medium-high heat. Add the marinated beef and stir-fry for about 3-4 minutes until browned. Remove the beef from the skillet and set aside.
In the same skillet, add the minced ginger and garlic. Stir-fry for about 30 seconds until fragrant.
Add the bell pepper, broccoli, and snap peas to the skillet. Stir-fry for 3-5 minutes until the vegetables are tender-crisp.
In a small bowl, mix together the honey, cornstarch, and water until smooth. Pour this mixture into the skillet and stir well to combine.
Return the beef to the skillet and cook for an additional 2-3 minutes, stirring constantly until the sauce thickens and coats the beef and vegetables.
Sprinkle sesame seeds over the stir-fry before serving. Serve hot over cooked rice or noodles.