Bring the soup to a boil in a saucepan. Add lemongrass and lime leaves then add crab tails and mushrooms.
simmer for 8-10 min. then remove from heat and add the remaining ingredients
Let stand for 5 minutes, then season and add lime juice or fish sauce if necessary.
Break the chillies so that they give off a little more heat. The soup should taste slightly sour spicy and slightly salty.
What goes well with it:
No potatoes but long grain rice no Mekong Wisky, but water or a light dry Riesling.