For the curry, remove the outer leaves from the lemon grass. Wash the stalks and flatten them slightly with the back of a knife. Peel onions, garlic and ginger, chop coarsely and puree to a paste with a hand blender.
Fry the paste in hot oil in a large pot at medium heat for about 1 minute, stirring continuously. Stir in star anise, cinnamon sticks, cardamom and curry leaves, continue to fry for about 1 minute. Add the stock.
Add curry and chilli powder, 2 teaspoons of sugar, 1 teaspoon of salt, pepper and lemongrass and bring to the boil.
Wash the chicken fillets, dab dry and cut each fillet into 4 pieces. Add to the curry with the butter. Bring everything to the boil again and simmer without lid on low heat for about 20 minutes until the curry is creamy.
For the coconut rice, wash the rice thoroughly in a large pot until the water remains clear. Pour off all the water. Add coconut milk, 150 ml water and 1 teaspoon salt to the rice. Bring to the boil over high heat, then cook over low heat according to the instructions on the packet.
Loosen up the finished rice with a fork. Sprinkle Kari Ayam with fried onions and serve with coconut rice.