Heat olive oil in a stockpot over medium-high heat.
Add onion and celery, and cook for 4-5 minutes, stirring.
Add the ground sausage and cook, breaking down the lumps, until the sausage is cooked through.
Add garlic and cook for 1 minute.
Add the liquid:
Pour in vegetable stock and scrape any browned bits. Add Italian seasoning, red pepper flakes, and tomatoes, and bring to a boil. Simmer for 5 minutes.
Add pasta:
Add pasta: Stir in the pasta, reduce heat, and simmer until al dente or according to package directions. Add drained beans and spinach.
Cook for 3 minutes.
Add the cheese.
Remove the stockpot from the heat and stir in Parmesan cheese.
Serve:
Serve warm, garnished with chopped parsley or desired fresh herbs.
Notes
This recipe can be made with or without meat. If you decide to omit the meat, increase the amount of beans and pasta accordingly.