Ingredients:
1 tablespoon extra-virgin olive oil
1 pound Italian sweet sausage, removed from casings
2 cups onion, diced
1 cup celery, diced
1 cup carrots, diced
2 cups red bell pepper, diced (about one large pepper)
2 tablespoons fresh garlic, minced
Pinch red pepper flakes
1/4 cup tomato paste
5 fresh plum tomatoes, diced
2 pounds zucchini cut into bite-sized pieces
1 teaspoon kosher salt
1/2 teaspoon freshly ground black pepper
2 quarts good quality vegetable broth
1 cup coarsely grated Parmesan cheese, plus more for serving
A few Parmesan cheese rinds (optional but recommended)
2 tablespoons fresh basil chopped
1 tablespoon fresh oregano chopped