Zucchini Tomato Italian Sausage Soup

extra-virgin olive oil

Italian sweet sausage, removed from casings

onion, diced

celery, diced

carrots, diced

red bell pepper, diced (about one large pepper)

fresh garlic, minced

red pepper flakes

tomato paste

fresh plum tomatoes, diced

zucchini cut into bite-sized pieces

kosher salt

freshly ground black pepper

good quality vegetable broth

coarsely grated Parmesan cheese, plus more for serving

few Parmesan cheese rinds (optional but recommended)

fresh basil chopped

fresh oregano chopped