Sweat the ginger and garlic in the butter, then add the chilli pepper and fry briefly. Deglaze with the canned tomatoes and bring to the boil.
Then add the coconut milk and let it reduce for 20 minutes over a low heat. Season well and let the prawns simmer in the hot, no longer boiling soup.
Fill into plates and add some fresh coriander or parsley, depending on your taste. If I serve the soup as a starter, I skewer the prawns on lemongrass and fry them in a little butter and curry and then decorate the skewers over a soup bowl.