Remove the outer leaves from the lemon grass, wash the stalks. Halve one, cut the rest into thin rings. Wash galangal and cut into slices
Peel prawns up to the tails. Fry the heads and shells in a large pan in hot oil for about 5 minutes. Add lemongrass stick, galangal, 2 l water and broth. Bring to the boil and let it simmer at low heat for about 20 minutes
Rinse and drain the mushrooms (clean the mushrooms, wash if necessary). Scratch the back of the shrimps and remove the intestines if necessary. Wash the prawns. Clean, wash and cut spring onions into rings. Clean and wash the chillies and cut them into rings with seeds
Sieve the broth. Simmer lemongrass rings, chillies, lime leaves, fish sauce, mushrooms and onions in the stock for about 2 minutes. Cook the prawns for another 2 minutes. Season to taste with lime juice. Jasmine rice tastes good with it