Wash the shredded jellyfish thoroughly. Blanch in boiling water for less than a minute. Drain and immerse the jellyfish in ice water. Change the water one or two times, and put in the refrigerator for 3-4 hours. Drain the jellyfish and chill well before serving.
Peel the cucumber and cut into half. Remove the seeds and shred finely.
Heat sesame oil in a wok and fry the garlic until golden and fragrant. Add chilli sauce, light soy sauce, fish sauce and lime juice. Bring to a low simmering boil. Dish out and leave aside to cool.
Add jellyfish into the sauce and toss well to mix. Arrange the shredded cucumber on a serving plate and serve with the jellyfish. Sprinkle over with sesame seeds.