For the cream of potato soup, lightly sauté the onion and leek in a little butter. Add potatoes, pour liquid and season with spices.
Cook for about 20 minutes, add the cream and cook for another 10 minutes. Puree with a hand blender or in a mixing glass (remove bay leaf first) and pass through a sieve if necessary, season again to taste.
Arrange in cups or plates. Garnish with glazed bacon and chopped herbs.