Potato-Leek Bisque

To prepare bisque: Heat oil in a Dutch oven over medium heat. Add leeks and 1/4 teaspoon salt. Cook, stirring occasionally, until very tender but not brown, 20 to 30 minutes. Adjust heat as necessary and add a bit of water if needed to prevent sticking. Set aside 1/3 cup of the leeks in a small bowl.

Add potatoes, milk and broth to the pot. Bring to a simmer (do not boil) and cook, stirring occasionally, until the potatoes are very tender, 10 to 15 minutes.

To prepare croutons: Meanwhile, add olives, anchovies and black pepper to the reserved leeks; mix well. Divide evenly among the toasted baguette slices.

When the potatoes are tender, remove from the heat. Puree the soup with an immersion blender or in batches in a regular blender. (Use caution when pureeing hot liquids.) Season with the remaining 1/2 teaspoon salt, lemon juice and white pepper. Divide among 8 soup bowls and float a crouton on top of each. Garnish with chives, if desired.