Potato and Leek Soup

INGREDIENTS:
3 tbsp butter (45 ml)
1 onion, chopped
1 1/2 cups leeks, white part and a little green, sliced thinly (325 ml)
3 Yukon Gold potatoes
6 cups chicken stock (1.5 L)
3 bay leaves
2 sprigs of fresh thyme
Juice of 1/2 lemon
Salt and pepper

DIRECTIONS:
Heat the butter in a large soup pot over medium high heat. Add onions and leeks and sauté until soft, about 3 minutes. Add potatoes, season and stir, coating well with melted butter. Add the stock, bay leaves and thyme and cook until potatoes are very soft. Puree soup in a blender or food processor, adding lemon juice and seasoning to taste.