Tomato Soup in a Bread Bowl

Name: Tomato Soup in a Bread Bowl
Ingredients: 5 tablespoons extra-virgin olive oil, plus more for drizzling; 1 large onion, sliced; 5 large cloves garlic, minced; 1 1/2 teaspoons dried oregano; Kosher salt; 1 28-ounce can whole peeled San Marzano tomatoes; 2 cups cubed peeled butternut squash (about 10 ounces); 4 cups low-sodium chicken broth; 2 tablespoons shredded parmesan cheese, plus a small piece of rind (optional); Freshly ground pepper; 4 8-ounce sourdough bread boules, top ½ inch sliced off, insides hollowed out to make bowls; 1 cup shredded mozzarella cheese (about 4 ounces); 1/2 cup heavy cream