Cook the sausage: Heat olive oil in a pot over medium heat. Remove sausage casings if needed, crumble the sausage, and cook until browned. Remove and set aside.
Sauté the vegetables: In the same pot, cook onion, carrots, and celery for 3 minutes. Add garlic, zucchini, and bell pepper. Stir and cook until tender.
Simmer the soup: Pour in diced tomatoes and chicken broth. Stir in kidney beans, basil, oregano, red pepper flakes, salt, and pepper. Bring it to a boil, then lower the heat and let it simmer for 15 minutes.
Add pasta and sausage: Return sausage to the pot. Stir in pasta and cook for 10 more minutes until the pasta is tender.
Serve and enjoy: Taste and adjust seasoning. Garnish with fresh basil and Parmesan cheese. Serve hot with crusty bread or a side salad.