Cut the lemongrass into small pieces, squeeze the lime. Chop the ginger, coriander and garlic into small pieces. Core and chop the chilli peppers. Cut the mushrooms into thin slices. Take the prawns out of the refrigerator.
Sauté lemongrass, ginger and 1 chilli pepper in oil over medium heat for 1 - 2 minutes. Deglaze with vegetable stock and let steep for 30 minutes. Then pour through a sieve and collect the liquid in a saucepan.
Add the fish sauce, lime juice, coconut milk and agave syrup. Add the mushrooms, garlic and the second chilli pepper, as well as about 10 prawns and half of the coriander and heat again. If you don`t like it so sour, only take half the amount of lime juice - give it a try!
In the meantime, fry the remaining prawns (seasoned with salt and pepper) in a pan with a little oil over medium heat for about 3 minutes on each side.