Drain and rinse the beans. Add the beans and vegetable stock to a large dutch oven. Bring to a boil over medium-high heat, skimming off any foam.
Add half of the chopped onion, 3 garlic cloves and the bouquet garni. Reduce heat to low, cover and simmer for 1 hour.
In a large skillet, heat the olive oil over medium heat. Add the remaining onion, garlic cloves, scallions and a pinch of sea salt. Sauté for 5 minutes.
Add the diced tomatoes with juice and cook for 5 - 7 minutes. Add this mixture to the dutch oven and stir to combine.
Add the cabbage, carrots, celery and zucchini. Season to taste with sea salt and ground pepper. Cover and simmer for an additional 30 - 45 minutes.
While the soup is simmering, make the pistou.
In a small food processor, add the garlic clove, spinach leaves, lemon juice and Parmesan. Pulse several times to process.
With the food processor running, slowly add the olive oil and process until smooth and creamy. Add a pinch of sea salt and ground pepper and pulse several more times to combine.
Add the Cavatelli and green beans to the dutch oven and simmer for 8 - 10 minutes until pasta is al dente.
To serve, spoon the soup into bowls, add a dollop of pistou and garnish with grated Parmesan. Serve immediately.