Pour water and vinegar into a saucepan, and bring to a boil over high heat. Stir in sugar, ginger, garlic, chilli and salt; simmer for 5 minutes. Stir in cornstarch. Remove saucepan from stove to cool.
Then transfer to a bowl, cover, and refrigerate until needed. Toss the Salad together and serve on its own or on top of bread, toast or roti. Drizzle the sweet and sour dressing and sprinkle toasted sesame seeds just before serving