Peel and finely chop the onion. Heat 40 g fat in a pot and fry the onion in it. Dust with flour and let it sweat on. While stirring, deglaze with stock and cream and bring to the boil. Pluck the chervil from the stems and chop finely.
Wash the chives, dab dry and cut into fine rolls. Add to the soup and stir in. Season to taste with salt and pepper. Pour into soup bowls and serve garnished with chervil as desired. Serve with flower croutons