Prepare the cucumber,cut in half lenghthways and scrape out the seeds with teaspoon. Cut in half crossways then cut each piece into matchsticks

Bring pan of water to boil,add chicken breast,and poach at a gentle simmer until cook through. Drain let cool

Shred the meat into small pieces over a bowl,letting any liquid fall into the bowl. Add the cucumber,celery, scallions,fish sauce,lime juice, chillies,mint,sesame seeds and sesame oil,and stir well. Spoon onto a serving platter and serve with wedges of lime