Dry-roast glutinous rice in a frying pan over low-medium heat, tossing or stirring, until it’s evenly pale gold in colour (4-5 minutes).
Add 4-5 thin slices of galangal, torn lime leaves and thinly sliced lemongrass and continue cooking, keeping it moving, until evenly golden brown and fragrant – the inside of the rice should still be white (2-3 minutes). Cool completely, then grind in a spice grinder or with a mortar and pestle.
Mince the chicken thighs until roughly the size of sunflower seeds.
Bring the chicken stock to a soft boil, add the minced chicken, then, with a large metal spoon, work quickly to toss the chicken so it cooks evenly (3-4 minutes). Once chicken is cooked through thoroughly and no longer pink, remove from heat – don’t let it overcook or the meat will be tough rather than springy and yielding.
Drain off most of the liquid, keeping a little so it just covers the chicken like a thin blanket – this stops the chicken drying out and adds the intense chicken flavour to the finished dish.
Transfer chicken to a bowl, and while still warm add 1 tbsp of the ground glutinous rice, then toasted chilli.
Stir and toss to distribute evenly through the chicken mixture. Add palm sugar, fish sauce and lime juice to taste.
To finish, add shallot, spring onion and all the soft herbs and toss gently until evenly distributed.