• 1 tablespoon unsalted butter
• 1 tablespoon olive oil
• 1 leek, white and tender green parts, rinsed and sliced [see Cleaning leeks below]
• 3/4 pounds carrots [about 5 or 6], diced
• 1/2 pound russet or Yukon gold potatoes, diced
• 2-1/2 cups stock or broth
• 1-1/4 teaspoons fresh thyme leaves [or 1/2 teaspoon dried]
• 2/3 cup half-and-half
• 2 tablespoon fresh lemon juice
• 1/4 teaspoon freshly grated nutmeg
• salt and freshly ground black pepper, to taste
• additional fresh thyme leaves, for garnish [or finely chopped flat-leaf parsley]

1. Heat a dutch oven or large soup pot over medium heat. Melt butter and combine with olive oil. Add leeks and sauté, stirring occasionally, about 4 minutes. Add potatoes and carrots and sauté for about 5 minutes, stirring occasionally.
2. Add stock and bring to a simmer. Add thyme, cover the pot and simmer until carrots and potatoes are tender, about 25 minutes. Purée the soup in a blender or food processor, in batches, if necessary. [Alternatively, use a handheld immersion blender in the pot.]
3. Return puréed soup to the pot. Add half-and-half, lemon juice and nutmeg. Season with salt and pepper to taste [using a light hand, depending on how salty your stock or broth is]. Bring to a simmer until just heated through. Ladle soup into bowls and garnish with fresh thyme leaves or parsley. Serve.

Cleaning leeks Leeks like to grow in sandy soil, so you need to clean them carefully. Slice off root end and most of the green tops. Slice leeks in half lengthwise. Rinse under running water, fanning layers to wash out any trapped grit. When they’re cleaned, slice crosswise in 3/4-inch pieces.

Serves: Makes 4 cups [3 to 4 first course servings]      Total cook time: X
Source: http://www.blue-kitchen.com/2009/01/28/potage-crecy-french-for-its-cold-outside%E2%80%94you-need-some-creamy-carrot-soup/ via Betsy