Cut bread into rhombs. Melt 10 g butter in a pan and roast bread in it while turning. Season with salt and paprika, take out. Wash parsley and watercress, shake dry.
Pluck the cress leaves from the stalks and, except for a few for garnishing, chop them finely with the parsley. Peel onion and chop very finely. Melt 20 g butter in a pot. Sauté the onion in it until transparent, dust with flour and sauté.
Gradually deglaze with stock and cream while stirring. Bring to the boil, season to taste with salt, pepper and sugar. Add the chopped herbs. Pour into small bowls, add a dash of crème fraiche and sprinkle with watercress leaves.
Add the croutons.