Sauté the onion, garlic, and bell pepper in olive oil until soft. Add in the diced Roma tomatoes and sauté on medium for 5-10 minutes.
Add the fresh spinach and sauté until barely wilted.
Stir in the pasta sauce and let simmer for about 10 minutes.
Combine sauce with pasta.
Pour into serving dish and top with Parmesan cheese and red pepper flakes!
*could add chicken sausage or chicken for protein!