Onions peel and cut into cubes. Peel garlic and chop finely. Peel and wash potatoes and cut into cubes. Heat butter and olive oil in a pot. Sauté onions and garlic for 2-3 minutes while turning.
Deglaze with wine. Bring to the boil. Pour in broth. Season with salt and pepper. Cover and simmer at low heat for about 20 minutes.
In the meantime, peel the carrot and slice lengthwise into thin slices. Heat the oil in a pot. Fry the carrot slices in it in 2 portions for 2-3 minutes until crispy. Drain on kitchen paper.
Wash sorrel and shake dry. Cut the leaves into fine strips, except for 4 to garnish.
Pour the cream into the soup and mix finely with a blender. Add sorrel strips, except for a few for garnishing, to the soup and puree briefly. Season to taste with salt and pepper. Arrange soup in bowls.
Garnish with crème fraîche and remaining sorrel. Add carrot chips.