Leek-and-potato soup

Instructions

• Trim root end of leeks and cut in half lengthwise. Leaving about 1 inch (2.5 cm) of pale green, cut off tough parts of leaves and discard. Separate remaining pale green and white leaves and wash under cold running water. Then slice leeks into 1/2-inch (1-cm) pieces. Coarsely chop onion.

• Melt butter in a large saucepan set over medium heat. Stir in leeks and onion. Sauté, uncovered and stirring often until softened, about 10 minutes. Add 4 cups (1 L) of broth. Bring to a boil. Meanwhile, peel potatoes and coarsely chop. You should have about 4 cups (1 L). Add to broth. Coarsely chop celery and carrots and add. Cover, reduce heat to low and simmer, stirring occasionally and scraping pan bottom, until potatoes are soft, about 30 minutes.

• Then purée vegetables in 2 to 3 batches in a food processor or blender until smooth. Return to saucepan. Stir in more broth, 1 cup (250 mL) at a time, until soup is as thin as you like. Taste when hot and add pepper and salt, if needed. Soup's flavor improves with overnight refrigeration and it freezes well. Add cream just before serving.