In a soup pot with a lid, heat the oil, two turns of the pan, over medium-high to high. Add the beef and cook, stirring occasionally and breaking up with a spoon, until browned, about 6 minutes. Stir in the potatoes; season with salt and pepper.
Finely chop the celery, pepper, onion, and garlic and add to the pot. Add the stock, tomatoes, herb bundle and cheese rind; partially cover and bring to a boil over high. Reduce the heat to medium and keep the soup at a low boil until the flavors from the cheese rind and herbs are released, about 10 minutes. Add the green beans and cook until crisp-tender, about 5 minutes more.
Discard the cheese rind and herb bundle. Serve the soup in shallow bowls, passing grated cheese at the table.
MORE:
Spaghetti with Sausage, Mushrooms and Fennel
