To make ground roast rice,place a thin layer of jasmine rice in a frying pan over a low heat or in a low oven and toast until it becomes opaque but not coloured. When cool,grind finely in a mortar.
To make the dressing,pound the garlic,coriander roots,chillies,sea salt and sugar in a mortar with a pestle to form a paste. Add the lime juice and fish sauce and taste to balance,adjusting if necessary.
Shred the iceberg lettuce and place on a plate.
Heat a wok until smoking. Add the peanut oil and,when hot,stir-fry the mushrooms and red onion for 30 seconds to 1 minute,until just starting to soften. Remove from the heat. Add the dressing,herbs and green onion and toss together. Spoon the mixture over the lettuce. Sprinkle the salad with fried brown shallots and ground roast rice to serve.
This dish could be served with a stir-fried omelet,a beef stir-fry and steamed snapper with shitake,proscuitto and bamboo shoots to make a perfect banquet for four.