Heat oil in a large saucepan over medium-high heat. Add onion and cook, stirring often, for 3-4 minutes until tender. Add carrots, celery, potatoes and zucchini and cook, stirring often, for 5 minutes

Stir in tomato paste and cook for 1 minute. Stir in tomatoes and stock. Cover and bring to the boil, skimming any froth from the surface. Reduced heat and simmer, stirring occasionally, for 30 minutes

Add cabbage and cook for a further 30-35 minutes until vegetables are very tender and soup is thick. Stir in beans and cook for 5 minutes. Stir in 
parsley. Ladle soup into serving bowls and serve with crusty wholegrain bread