Put the chicken into a pan with 1 tsp salt, the ginger and enough cold water to cover. Finely shred the spring onions and add half to the pan.
Bring to a simmer and poach gently for 15 minutes. Turn off the heat and leave for 30 minutes, then drain.
Cut the cucumber, carrot and celery into matchsticks. Finely shred the chicken and combine with the cucumber, carrot , celery and the remaining spring onions.
Add the sesame oil and vinegar, sea salt and pepper and toss to mix. Arrange in four bowls or platters.
To make the sauce mix the sesame oil, peanut butter, chilli sauce, soy sauce, sugar, vinegar and sliced chilli until you have a paste. Gradually whisk in up to !00 ml water until runny but still quite thick
Spoon the sauce over the chicken and vegetables, scatter with toasted sesame seeds and serve.