Heat the oil on a large (6 quart) dutch oven over medium heat. Add the leek, potato and garlic. Cook, stirring often until everything is slightly browned and aromatic; about 10 minutes. Add the wine and continue to sautee for a few minutes until much of the liquid has evaporated. Add the chicken stock and bring to a boil. Reduce the heat and allow the soup to simmer for 45 minutes - the potatoes especially ought to be very very soft. Working in batches, blend until smooth. Return all the soup to the pot and gently stir in the cream. Then add the lemon juice. Ladle into bowls and top with parsely or chives for garnish. LOVELY. SOUPER!! Enjoy, Natalia