In a large pot heat olive oil, add onions, and cook until soft (about 5 minutes)
Add carrots, celery, Italian seasoning, 1 teaspoon rosemary, salt and pepper. Cook for an additional 2-3 minutes. Stir in garlic until fragrant (1 min more).
Add chicken broth, beans, parmesan rind (if using), lemon juice and lemon zest. Bring to a boil, reduce heat, and simmer for 15-20 minutes. Remove parmesan rind.
Stir in spinach, simmer another 2 minutes. Season to taste.
To serve, sprinkle with grated parmesan cheese, and garnish with a sprig of rosemary.
Notes
Nutrition calculated without parmesan rind.
I used 4 cups broth, but if you want the soup not as thick use more.
Refrigerate cooled leftovers in an airtight container for up to 4 days.
Freeze portions in airtight containers for up to 3 months.