Toast the coriander and cumin seeds in a frying pan over medium heat, stirring and taking care not to let them burn, then grind in a mortar and pestle or spice grinder.
In a bowl, combine the yoghurt, turmeric, curry powder and 1 teaspoon of the ground coriander and cumin seeds. Add salt, soy sauce and coconut milk, mix well. Add the chicken and toss to coat well. Cover with plastic wrap and marinate in the fridge 2 hours or overnight.
Remove the chicken from the yoghurt sauce and thread onto bamboo skewers. Heat the barbecue and oil the plate. Cook skewers, turning frequently and basting with coconut milk until cooked. Serve with satay sauce.
Satay sauce
Heat the vegetable oil in a small saucepan. Add curry paste and fry until it starts to smell. Stir in coconut milk, palm sugar and tamarind sauce. Cook, stirring, until sugar has dissolved and sauce has thickened slightly.
Remove from heat and add fish sauce and peanuts. Stir and serve!