- Heat oil in a large saucepan over medium-high heat. Add carrots, zucchini, celery and onion. Cook, stirring occasionally, for 10 minutes or until vegetables begin to soften.
- Add tomatoes and stock to pan. Cover and bring to the boil. Reduce heat to medium-low. Simmer, partially covered, for 15 minutes or until vegetables are soft.
- Add lentils to soup. Cook for 5 minutes or until heated through. Ladle soup into bowls. Sprinkle with parsley and squeeze lemon juice. Season with freshly ground black pepper. Serve with lemon wedges.