In a large pot or Dutch oven, melt butter with olive oil over medium heat.
Add celery, carrots, potatoes, onion, and garlic to the pot. Cook until vegetables are slightly softened, about 5 minutes.
Stir in prosciutto and cook for an additional 2-3 minutes.
Add chicken stock, bay leaf, parsley, basil, Pecorino Romano rind (if using), and salt and pepper to taste.
Bring soup to a boil, then reduce heat to low and simmer for 30 minutes.
Add beans, green beans, cabbage, zucchini, and diced plum tomatoes to the soup. Simmer for an additional 20 minutes or until vegetables are tender.
Remove bay leaf and Pecorino Romano rind (if using) from the soup.
Serve hot with grated Pecorino Romano cheese on top.
Notes
– Use fresh vegetables for the best flavor.– Use canned tomatoes for convenience.– Use any type of small pasta that you have on hand.– Make a large batch and freeze for later.– Add some grated Parmesan cheese for extra flavor.