Heat the olive oil in a large pot over medium heat. Add the onion and cook until translucent, 3-4 minutes. Add in the garlic and cook for a minute or so more, until fragrant.
Add the sausage to the pot and cook until completely browned, breaking it up as you go. Drain any excess grease, if needed.
Increase the heat to med-high. Add the carrots to the pot, then stir in the broth, water, diced tomatoes, beans and seasonings.
Once it all comes to a boil, stir in the orzo and zuchinni, then lower the heat back down and let simmer for 7-8 minutes, until the veggies have softened and the orzo is close to al dente. Make sure to stir often during this time, so the orzo won't stick to the pot.
Stir in the spinach and simmer just 2-3 minutes more, until it's wilted.
Serve immediately, topped with fresh parmesan cheese, if desired. Sprinkle red pepper flakes over individual portions for a bit of extra heat.
Refrigerate any leftovers in a large Tupperware container. To reheat, place the amount you want warmed in a small pot (add a splash of broth if needed, the orzo will absorb a lot of the liquid during frigeration) and bring to a simmer for 5 or so minutes, until heated through.
