This is from our intern Sombat Moontha -an authentic recipe.
300 g. chicken meat
1 can coconut milk
8-9 sliced galangals (similar to Ginger root)
4-5 fresh chilies
6-7 kaffir lime leaves
2 lemon grass stems
2 sprigs cilantro
1 tsp salt
3 Tbsp thin soy sauce (or fish sauce)
1 Tbsp sugar
3 Tbsp lime juice
2 cups water
1. Wash galangal, lemon grass, and kaffir lime leaves, then pat dry. Slice galanga and lemon grass stem, tear kaffir lime leaves in halves (remove central stems).
2. Wash mushroom, fresh chilies, and cilantro, then pat dry. Cut mushroom in six-eight parts, slice chilies, and coarsely chop cilantro.
3. Wash chicken, pat dry and cut into pieces.
4. Pour coconut milk and 1 cup water in a pot, bring to boil on medium-high heat, add sliced galangal, sliced lemon grass and torn kaffir lime leaves, then let them boil about 5 minutes.
5. Add cut chicken, wait until the chicken is getting cook, add salt and stir well.
6. Add coconut cream, stir thoroughly, then add 1 cup water and bring to boil.
7. Add sliced mushroom and chilies, stir well and turn off the heat.
8. Season with thin soy sauce (or fish sauce), sugar, and lime juice, taste as you like, then add chopped cilantro and stir well.
9. Put chicken in coconut soup in a bowl, sprinkle with cilantro and serve.