Heat oil in a large saucepan over medium heat, add pancetta, leek, garlic, carrots, fennel and potato. Cover with a lid and cook, stirring occasionally, for 10 minutes or until vegetables are softened. Add tomato paste, cook, stirring for 1 minute.
Add stock and tomatoes, and bring to a simmer. Simmer uncovered for 10 minutes. Stir in pasta. Cover and cook for a further 8 minutes or until pasta is al dente.
Stir in the cabbage until just wilted. Scatter over the parsley and season. Ladle soup into bowls. Serve with parmesan and toasted crusty bread.