Prep the beef - In a bowl mix together the thinly sliced beef, corn starch and soy sauce. Mix so the beef is well coated. Set aside by your cooking station.
Prep the veggies - cut the scallions to separate the white from the green part. Dice the white part into small pieces. For the green part leave them longer by cutting them into 2 inch long pieces. Reserve a few stalks of the scallion greens for garnish. Mince the ginger, and garlic. Cut the green peppers into small 1 inch square pieces. Set aside by your cooking station.
Prep the sauce - In a small bowl mix together all the sauce ingredients and set aside by your cooking station.
Cook the noodles - prepare the noodles according to the package directions. Drain and set aside.
Heat a large wok with 2 tbsp oil.
Add the beef strips in a single layer. Do not mess with them for 1-2 minutes. Let them cook on medium high heat so the bottom parts that are touching the bottom of the pan get a nice golden brown caramelization. Once they start browning on the bottom, give it a stir and stir-fry till the beef is no longer pink. About 2-3 minutes. Remove from the pan and set aside.
In the same wok, heat another 2 tbsp of oil on medium heat. Add the minced ginger, garlic, whites of the scallion, whole dried red chilli, and green chilli, if using. Stir fry till fragrant, about 1-2 minutes. Add the cumin and red chilli powder and stir fry for an additional 30 seconds. Add the stir fry sauce, greens of the scallion and green pepper. Allow the mixture to come to a boil.
Add the prepared noodles and stir fried beef and mix well to combine. Allow to cook for an additional 2-3 minutes for the flavours to come together. Taste and adjust for salt or spice level to your liking. This is supposed to be a slightly spicy dish!
Serve warm topped with chilli oil and more chopped scallion greens for garnish. Enjoy!