Heat the olive oil over medium-high heat in a large (5-quart or larger) pot or dutch oven (here's the one I own and love!) Add the onion, carrots, celery, zucchini, garlic, Italian seasoning, salt, and pepper. Stir and cook for 5 minutes to allow the vegetables to soften. Add the tomato paste and cook for 1-2 minutes.
Add the broth, water, bay leaves, all the beans, and diced tomatoes. Stir together. Bring to a boil, then add the uncooked pasta. Reduce the head to medium, cover and summer for 10-12 minutes or until the pasta is cooked. Stir in the chopped spinach and lemon juice. Simmer for 2-3 more minutes. Remove both bay leaves.
Serve soup warm and top with fresh parmesan cheese, if desired.
Store leftovers in an airtight container in the refrigerator for up to 1 week. To reheat, pour into a pot over medium heat and cook until warm. Likewise, it can also be heated in the microwave. Feel free to add more broth or water if it's too thick— I usually do. The pasta tends to soak up the broth.
Make ahead tip: The soup freezes well. Freeze for up to 3 minutes. Thaw in the refrigerator the day before, then reheat as desired.Slow cooker directions: Add all the ingredients to the slow cooker, except the pasta or rice, spinach, and lemon juice. Cook on low for 3 hours, then add the pasta or rice, spinach, and lemon juice. Cook on low for 1 more hour. Add the lemon juice and give it a quick stir.1If you don't have Italian seasoning on hand, you can use equal combination of dried basil, oregano, parsley, etc. totaling 1.5 Tablespoons.2Use your favorite combination of beans. I've used chick peas in this recipe as well!3Any type of pasta or rice works, but just make sure it's smaller in shape.