Curry Carrot-Leek Soup

In a large saucepan, saute leeks and carrots in butter until leeks are tender. Add potato and curry powder; cook and stir for 2 minutes. Add broth, salt and pepper; bring to a boil. Reduce heat; cover and simmer for 15-20 minutes or until the vegetables are very tender. Cool slightly. Process in batches in a food processor or blender until pureed. Return to the pan; heat through.