Heat oil in a large pot over medium-high heat. Add fennel, onion and celery and saute until softened (7-9 minutes). Add garlic, oregano and pepper flakes and cook one minute more. Stir in tomatoes and beans and simmer for 10 minutes on medium-low heat.
Add broth and cook for 20 minutes, stirring occasionally. Stir in pasta and cook for 10 minutes more, or until pasta is al dente.
Season with salt and pepper to taste and turn off heat. Stir in parsley and serve.