In a small bowl, combine all the ingredients for the sauce. Set aside.
Separate and wash the lettuce leaves, spin the leaves dry in a salad spinner and set them aside in the refrigerator.
Heat a wok or large frying pan over high heat until it is hot. Add the oil, and when it is very hot and slightly smoking, add the garlic, shallots and chillies and stir-fry for 2 minutes. Then