We stirred harissa, a hot chile sauce commonly used in North Africa, into this carrot-and-leek soup for a hint of heat.
Heat oil in a large saucepan over medium heat. Cook leek until just soft, 4 to 5 minutes. Stir in carrots and harissa. Season with salt. Cook until carrots are just soft, 8 to 10 minutes. Add chicken stock, and bring to a simmer. Cook until vegetables are tender, 10 to 12 minutes.
Puree half the soup in a blender until smooth. (For safety, remove cap from hole in lid, and cover with a dish towel to prevent spattering.) Stir puree into remaining soup in pan. Divide soup among 4 bowls, and garnish with parsley.