In a food processor or blender, whizz the garlic, half the sugar and half the soy sauce with the ground turmeric and coriander, chilli flakes, lemongrass, oil and half the coconut milk to form a smooth paste.
Mix the coconut milk mixture with the chicken, cover and leave to marinate in the fridge for at least 1 hour, although the longer the better. Remove the chicken from the fridge about 20 minutes before you plan to cook it.
In the food processor/blender, whizz half the peanuts together with the remaining sugar, soy sauce and coconut milk and the juice of 1 of the limes. Put to one side. Heat the oven to 200°C fan/gas 7. Arrange the chicken and any excess marinade on a baking tray along with the spring onions.
Bake for 35-40 minutes until the chicken is golden, beginning to char and cooked through. Remove from the oven and drizzle with the coconut–peanut sauce, then sprinkle with the remaining peanuts (or serve alongside to sprinkle individually), the fresh chilli and chopped coriander. Cut the remaining lime into wedges for squeezing over.
