1.Combine chicken, kecap manis, sugar, ginger and sauce in large bowl. Cover; refrigerate 30 minutes.
2.Meanwhile, make pickled cucumber. Stir vinegar, salt and sugar in medium bowl until sugar is dissolved. Cut unpeeled cucumbers into 1cm thick slices. Using teaspoon or melon-baller, remove about half the seeds from each slice to allow space for the chicken pieces. Add cucumber to vinegar mixture, stand 10 minutes; drain on absorbent paper.
3.Cook chicken in large oiled frying pan over medium heat until golden brown and cooked through.
4.Top each cucumber slice with a piece of warm chicken; sprinkle with a little chilli. Serve immediately.