Heat oil in a large stockpot over medium heat. Add onion, bell pepper and garlic, and sauté for 3-4 minutes.
Stir in the ground beef and cook, stirring and breaking the meat, until no longer pink, about 5-7 minutes.
Add in diced tomatoes, Parmesan rinds, Italian seasonings, broth, a pinch of sea salt, and pepper.
Bring to a boil, then reduce the heat, cover and simmer for 25-30 minutes.
Stir in the zucchini noodles, and simmer for additional 1-2 minutes.
Remove Parmesan rinds and discard.
Serve soup hot, garnished with fresh chopped herbs such as basil and parsley.