Boil the wheat noodles in salted water exactly according to instructions (al dente). Drain, rinse with cold water to stop cooking, and let them drip dry. (Crucial for preventing sticking).
Dice the chicken meat and marinate it for 15 minutes in 1 tbsp of Ketjap Manis and seasoning.
Heat the oil in a Wok or large deep pan over high heat.
Sauté the onion and garlic. If using Trassi, add it now and fry until the aroma is released.
Add the marinated chicken and fry until cooked and golden.
Add the chopped vegetables (Bok Choy, leek, etc.) and fry for 2 minutes.
Add the boiled noodles, the crushed Maggi cube, the remaining 2 tbsp of Ketjap Manis, and 1 tbsp of Ketjap Asin to the pan.
Stir quickly and thoroughly, preferably with two spatulas, so the sauces are evenly distributed. The noodles should achieve a uniform dark color. Stir-fry for 3-5 minutes.