
In a small bowl, whisk together the kecap manis, fish sauce, white pepper, and chilli crisp until well combined. Cut the chicken into bite-size pieces, then toss it with 2 tbsp of the sauce.
Heat the peanut oil in a large nonstick skillet or wok over high heat until very hot. Add the chicken and stir-fry for about 2 minutes, or until lightly browned. Add the garlic and the white parts of the green onions, then cook for 30 seconds more.
Add the shredded cabbage and stir-fry for 1 to 1 1/2 minutes, until it begins to soften but still has a little texture.
Add the noodles and half of the remaining sauce. Toss for about 45 seconds, until the noodles absorb the sauce. Pour in the rest of the sauce and continue tossing for 1 minute, until everything is evenly coated and no excess liquid remains in the pan.
Stir in the green parts of the green onions and cook for 15 to 20 seconds, just until wilted. Divide among bowls and serve immediately.