Cut the melon in half and remove the seeds. Next, using a baller, cut out a few balls of pulp for decoration.
Scoop out remaining pulp. Peel off crab tails and remove intestines.
Remove shell from onion, chop and sauté in a frying pan with 1 tbsp clarified butter. Add the shrimp shells and about 3 tbsp of melon and sauté.
Extinguish with the clear soup. Remove the shells again. Add the rest of the melon, mash everything together, pass through a sieve and season with salt, pepper and a pinch of sugar. Finely chop the tarragon, mix into the soup and leave to cool. Roast the crab tails in a frying pan with 1 tbsp. clarified butter. Add the melon balls and sauté briefly.
Arrange the cold soup and bring to the table with the hot crayfish tails and melon balls.
Tip: Instead of clarified butter, you can also use butter in most cases.