Peel and finely dice the shallots. Cut the lemongrass into small pieces and sauté with the shallots in clarified butter. Add the flour, stir well and deglaze with the vegetable stock.
Let the soup simmer for about 15 minutes and add the white wine, season and strain through a sieve. Refine with the cream. (the soup will be creamier with whipped cream).
Peel the prawns, pat dry well with kitchen paper, cut open towards the tail like a butterfly and remove the intestines. Season with salt and pepper and fry briefly on all sides in hot olive oil. Drain tightly on kitchen paper and serve in the soup. - more / or less than 2 pieces per person can be used, depending on your mood-