Peel and wash the potatoes and carrots and cut them into small cubes. Clean, wash and cut leek into rings. Heat oil in a pot. Sauté the vegetables in it. Add stock, bring to the boil and cook for about 15 minutes.
Remove 1/3 of the vegetables from the soup. Puree the soup. Stir in Crème balance. Add vegetables to the soup. Season soup with salt and pepper. Leave bacon in a pan until crispy. Drain on kitchen paper.
Cut the bacon into small pieces. Arrange soup on plates. Spread bacon on top.