Onions peel, halve and in strips cut. Remove the outer rind from the lemon grass, chop the inside roughly. Peel and chop the ginger and garlic. Heat the oil in a pot.
Briefly sauté the onions, lemongrass, ginger, garlic and curry paste in it, then deglaze with broth and coconut milk. Bring to the boil and simmer for about 30 minutes.
In the meantime clean, wash and slice the mushrooms. Peel carrots and cut into small pieces. Clean, wash and slice the zucchini. Put the bamboo strips in a sieve and let them drain.
Wash and clean spring onions and cut into rings. Put the sprouts in a sieve and rinse briefly under cold water.
Wash the meat, dab dry and cut into strips. Pour stock through a fine sieve into a pot. Add chicken, mushrooms, carrots, bamboo strips and zucchini, bring to the boil and simmer for 5-6 minutes.
Add sprouts and spring onions about 1 minute before the end of the cooking time. Season soup with soy sauce, sugar and lime juice to taste. Wash the coriander, shake dry and chop the upper 1/3 of the stems coarsely.
Arrange the soup in bowls and sprinkle with coriander.