We start by making the marinade where we add in a glass bowl the sugar, half the soy sauce, the lime zest and the black pepper. Whisk well and keep aside.
Cut the flap steak against its grain into 3-4 mm thickness strips and add into the bowl with the marinade. Toss well to get coated and allow for the flavours to infuse into the meat for 30’.
We make the sauce by taking another bowl and add the corn-starch, rice vinegar, teriyaki sauce, lime juice, sesame oil, and the remaining soy sauce. Whisk well and keep aside.
Set a large wok pan or cast-iron skillet over high heat and let it heat up for 2 minutes until smoking. Add 15ml of the peanut oil and let this heat up for 1 minute. Add the strips of the flap steak, and stir-fry for 3 minutes and until lightly browned. Take off the heat and place the cooked strips of the flap steak and allow to rest in a plate, covered with foil, for 7-8 minutes.
In the same wok or skillet add the remaining 25ml of the peanut oil. A minute later toss in the ginger chilli pepper and the garlic and stir-fry for 45’’. Toss in the carrots, bell peppers and snow peas and continue stir-frying for 1 more minute.
Without delay add the strips of the flap steak (without its juices) and the sauce and stir-fry for just over a minute for the flavours to come together.
Serve next to the noodles, sprinkle with sesame seeds and top with the fresh onions.