In a large pot, heat the olive oil (or bacon grease) over medium heat. Add the chopped onion, celery, and garlic. Cook for about 15 minutes, or until the vegetables start to soften.

Add 3 cups of chicken broth and a can of diced tomatoes to the pot. Stir to combine.

In a blender or using a hand blender, blend 1 cup of chicken broth with the drained and rinsed white beans until smooth. Pour this bean mixture into the soup.

Add dried rosemary, bay leaves, dried basil, minced parsley, and salt and pepper to taste. Stir everything together.

Bring the soup to a boil, then reduce the heat to a simmer. Cover and let it simmer for about 40 minutes.

After 40 minutes, remove the cover, and add the diced zucchini and 2 cups of fresh or defrosted frozen spinach. Cover and simmer for an additional 10 minutes.

While the soup is simmering, cook the ditalini pasta separately according to the package instructions.

Remove the bay leaves from the soup.

To serve, place a desired amount of cooked ditalini pasta into each bowl, then ladle the soup over the pasta.

Garnish with grated Parmesan cheese, if desired.