Mix together the cornstarch, soy sauce, and peanut oil in a large bowl then stir in the strips of steak to coat evenly. Set aside to marinate.
Mix together the soy sauce, sesame oil, and black pepper. Set aside.
Cook the noodles about a minute shy of package directions (the noodles will cook a bit more in the stir-fry) then drain and rinse under cold water. Set aside.
Heat a wok or large pan over high heat until very hot.
Add 1 TBSP of the oil to the pan then tilt the pan to coat.
Add the beef to the pan and stir-fry until browned, about 90 seconds then transfer the seared beef to a plate and set aside.
Add 1 TBSP of oil to the pan then add the bell pepper, carrot, garlic, and broccoli and stir-fry for about 30 seconds.
Add the noodles to the pan and stir-fry for about 30 seconds.
Add the SAUCE to the pan and stir-fry for about 30 seconds.
Add the beef to the pan and stir-fry for about 30 more seconds then take the pan off the heat.
Add the green onion to the pan then taste the noodles and seaon with additional salt & pepper if needed.
