Step 1 Heat oil in a large saucepan over medium heat. Add onion, celery, carrot, parsnip and garlic. Cook, stirring occasionally, for 5 minutes. Increase heat to high. Add lamb and cook for 5 minutes, or until browned all over. Add tomato paste. Cook, stirring, for 1 minute.
Step 2 Add chopped tomatoes, stock and 2 cups water to saucepan. Bring to the boil, then reduce heat to low. Simmer, partially covered, for 1 hour, stirring occasionally.
Step 3 When ragu is almost cooked, cook pasta in a separate saucepan according to packet instructions.
Step 4 Mix half the ragu through pasta, then spoon into bowls. Top with remaining ragu. Sprinkle with parmesan and parsley.