1. Preheat the oven to 200 degrees and prepare the broth.
2. Slice the onion and crush or finely chop the garlic.
Cut the carrots into thin half-rounds and the tomatoes into quarters.
Chop the basil.
3. In a soup pot, heat the olive oil and sauté the onion and garlic for 2 minutes over medium-high heat.
Add the carrots and tomatoes, then stir for 4 minutes.
4. Add the broth, cover, and cook the soup for 12 to 15 minutes over medium-low heat.
5. Meanwhile, bake the raisin and walnut bread for 6 to 8 minutes.
6. Drain the buffalo mozzarella and tear it into small pieces.
7. Off the heat, blend the contents of the pot using an immersion blender.
Add water if necessary to thin the soup. Season with salt and pepper.
8. Open the small bread and fill it with half of the mozzarella.
9. Serve the soup in bowls, then garnish with the remaining mozzarella and basil.
Serve with the raisin and walnut bread.