Wash vegetables. Peel the carrots, onion and garlic. Chop the carrots, celery, onions and garlic. Heat the oil in a saucepan and sauté the onions and garlic. Add the carrots and celery and sauté for 5 minutes. Add the chestnut flour and thyme. Add the vegetable stock. Boil the soup with the lid on for 10 minutes until soft. Puree the soup, and add cream and vinegar. Simmer again for 5 minutes. Season with salt and pepper and serve with parsley. TIP: Instead of 50 g of chestnut flour, you can use 140 g of freshly peeled chestnuts.