For the sauce, stir ketcup manis and sweet chilli sauce together. Set aside.
Process garlic, chilli and ginger until very finely chopped, almost paste-like. Pour half the oil into a cold wok then add the chilli mixture. Turn heat to medium and stir-fry until aromatic. Add eschallots and stir-fry for 2-3 minutes, until soft. Remove mixture to a bowl.
Increase heat to high, once wok is hot add remaining oil and mince, stir-fry until colour changes. Add Fioretto, stir-fry for 2-3 minutes until all liquid evaporated. Add eschallot mixture back and stir-fry until well combined. Add ketcup manis and stir to coat then add water chestnuts, stir fry until well combined.
Spoon in lettuce cups, drizzle with sauce then top with beansprouts, coriander and fried eschallots to serve.