In work bowl roughly chop the carrot, onion and herbs.
Saute in the butter.
If using whole crayfish, split the crayfish into halves, remove the coral, the creamy parts and the liquid, squeeze through a sieve and reserve.
Add the split crayfish (or fresh prawns or crayfish shells or prawn shells) to the vegetables, season and cook slowly until they turn red (approximately 5-10 minutes).
Flame with cognac, add the white wine, the fish stock, the fresh tomatoes (previously chopped in processor) and the tomato puree.
Season and cook covered for 20 minutes.
Remove the crayfish tails or prawns, take out the flesh and save.
Return the shells to pot, add the rice and cook for 30 minutes.
Place all the contents of the pot, including the shells, 2 cups at a time in the work bowl and process for 20 seconds.
Strain through a medium sieve.
If using crayfish add the previously sieved internal parts.
Add the cream and the cayenne pepper.
If necessary adjust the seasoning.
Cut the flesh of the crayfish tails or the prawns into large dice and add to the bisque or add diced white fish.