Clean the mushrooms, wash and halve them. Wash the chicken filet, dab dry and cut into pieces. Wash the chilli, cut lengthwise and remove the seeds. Cut chilli into fine rings.
Wash lemon grass and kaffir leaves, shake dry. Cut lemongrass into pieces of about 3 cm length and beat them. Wash, peel and thinly slice the galangal. Heat oil in a pot.
Carefully sauté galangal, lemon grass and kaffir leaves in it. Deglaze with coconut milk and poultry stock and simmer at medium heat for 2-3 minutes. Wash the tomatoes and dab dry. Add meat, mushrooms, bean sprouts, tomatoes and chilli, cover and simmer for about 5 minutes.
Set aside some coriander for garnishing. Remove the coarse stems from the remaining coriander and basil. Stir the herbs into the soup, cover and let it simmer for about 5 minutes. Season the finished chicken soup with fish sauce and lime juice.
Remove any lemon grass and lime leaves. Serve the soup. Add the lime wedges. Crab bread tastes good with it.