Remove the skin from the thighs and separate the thighs at the joint. Rinse the pieces well and simmer in plenty of water for 5 minutes. Strain and rinse the pieces. Discard the cooking water.
Cap the onions and garlic cloves at both ends, peel and roughly chop. Fry in a pan with the sunflower oil until translucent. Wash the tomatoes, remove the stem, cut in half lengthways and remove the green stem. Halve the halves lengthways and thirds across. Wash the small, green chilies, cut into thirds crosswise, leave the grains in place, discard the stem. Wash, peel and cut the galangal into thin slices. Roast the coriander seeds in a pan without oil at 160 degrees. Wash the red peppers and cut across into pieces approx. 6 mm wide. Leave the grains, discard the stem.
Put all the ingredients for the broth in a 1.5 liter saucepan (with a lid) and heat while stirring so that the sugar is dissolved. Simmer with the lid on for 10 minutes. Take off the stove and let cool down a bit.
Pour the stock into a blender and purée finely for 1 minute on the highest setting. Return to the pot. Squeeze the juice from a ripe lime. Add the chicken thighs, the spices and coconut milk. Simmer for 45 minutes and let thicken a little. Remove the leaves and use for garnish.
Strain the chicken thighs and let them dry a little. Remove the leaves and use for garnish. Heat the deep-frying oil to 220 degrees and deep-fry the chicken thighs in 2 portions until light brown.
Drain the chicken thighs ala Kalasan on paper towels, then distribute them on the serving plates. Pour some of the broth into 2 bowls, garnish with coconut milk and the leaves. Serve with a spicy sambal matah, boiled rice and the chicken thigh ala Kalasan.