Wash the chicken breast fillet, pat dry with kitchen paper, cut first into slices and then into strips. Peel and finely dice the ginger. Clean the lemongrass and cut into 3 pieces each. Clean and wash the spring onions and cut into fine rings. Clean / core the chilli pepper, wash and finely dice. Clean and wash the coriander, shake dry and finely chop. Chop the chicken from the chicken broth. Put the chicken broth (340 ml from a glass), coconut milk (250 ml) and water (660 ml) in a saucepan, add the ginger cubes, lemongrass pieces and kafir lime leaves (4 pieces) and simmer / cook for about 20 minutes. Remove the lemongrass pieces and lime leaves and add the strips of chicken breast fillet, finely chopped chicken from the chicken stock, spring onion rings, diced chili peppers and finely chopped coriander. Season with fish sauce (1 teaspoon), lemon juice (1 teaspoon), brown sugar (1 teaspoon), instant chicken broth (1 teaspoon) and sambal oelek (½ teaspoon). Let everything simmer / boil for about 5 - 6 minutes. Finally, thicken with tapioca starch (2 tbsp) dissolved in a little cold water. Wash the chives, shake dry and cut into fine rings. Fill chicken soup with coconut milk into soup bowls and serve sprinkled with chives.