Pat the skirt steak dry with paper towels. Place the beef in a large mixing bowl and season with salt, pepper, and cornstarch;Toss to combine and set aside.
Heat a wok or large skillet over medium-high heat and add 1 tablespoon of olive oil. When oil is hot, add green beans and saute for 2 minutes. Add 1 tablespoon of water and cover the pan. Continue cooking for 5 more minutes.
Use tongs to transfer the green beans to a plate and set aside. Use a paper towel to wipe any excess water out of the pan.
Add the remaining tablespoon of olive oil to the hot pan. Add beef and stir fry for 4-5 minutes. Reduce the heat to medium, then add soy sauce, garlic, ginger, rice wine vinegar, and sesame oil. Use tongs to coat the beef in the sauce.
Add the green beans back to the pan and stir fry everything together for an additional minute.
Garnish ginger beef with sesame seeds and chopped green onions on a bed of rice or noodles.