Place sliced steak, egg and salt into a mixing bowl and toss together until beef is fully coated. Allow mixture to sit for 10 minutes.
Pour all sauce ingredients into a mixing bowl and whisk together. Set aside.
Drain excess egg from bowl of beef, sprinkle cornstarch over beef and toss together until evenly coated.
Place large skillet over medium-high heat and add 2 tablespoons oil. Add beef in a single layer and sear for 3 minutes. Flip and sear for an additional 2 minutes. Then transfer beef to a plate.
Pour remaining oil into skillet, increase heat to high heat and sauté onion, bell pepper and chile peppers, about 2 to 3 minutes.
Add ginger and garlic and stir together until evenly distributed.
Lower heat to medium-high and stir in sauce. Allow sauce to thicken, about 1 minute.
Add beef back to skillet and toss together until evenly coated.
Remove skillet from heat, top with toasted sesame seeds and serve.
