Top and tail the haricots verts and halve them. Finely chop the onion. Halve the sweet pepper, remove the seeds and slice the flesh into cubes. Halve the cayenne pepper lengthwise, remove the seeds and finely slice the flesh.
Heat the olive oil in the wok and stir fry the onion and sweet pepper on a medium heat for 3 minutes. Press the garlic above the wok and add the haricots verts. Stir fry for another 2 minutes.
Add the cayenne pepper and ketjap and simmer on a low heat for about 8 minutes until the haricots are cooked.
Variation tip: Sprinkle the haricots verts with roasted grated coconut or serundeng.