Pound the garlic and chilli together for a couple of minutes, until you have a coarse paste.
Leaving this paste in the mortar, add your cabbage, and gently break up the fibres with the pestle.
Add the rest of the dressing ingredients and the peanuts, plus the remainder of the vegetables, and continue to gently pound, while moving the salad around the mortar to ensure everything receives its fair share of the dressing and paste. Do this for five minutes or so.
Pile the som tam onto a couple of plates, drizzle over any dressing left in the mortar, and top with some spring onion and a little bit of coriander leaf (cilantro).
Pound the garlic and chilli together to make a paste, place in a small jug or bowl.
Add the rest of the dressing ingredients, and mix well, until the sugar has dissolved.
Taste, and adjust if necessary; the flavour cycle needs to be hot, sour, salty, sweet – in that order.
Put the salad ingredients into a large bowl, and pour over the dressing.
Toss everything together, so that all the veggies are well-coated.