Heat the olive oil in a large heavy-bottomed pot or Dutch oven over medium heat. Add the onion, carrot, zucchini and celery. Cook until the vegetables have softened, about 7-8 minutes. Add the garlic cloves and a pinch of salt and pepper. Add the beans, the potato, chopped tomatoes in their juices, and the vegetable stock. Bring to a boil, stir and then reduce the heat to low. Add the fresh herbs, cover the pot and let it simmer for about 20 minutes.