- Heat a large pot over medium heat until hot.
- Add oil and onion, and cook until onion has softened, about 5 minutes.
- Add garlic, celery, carrots and zucchinis and cook for 2 minutes.
- Add the cannellini beans and stock and bring to a boil, then turn heat down and simmer for 10 minutes.
- Remove from heat and using a stick blender (or transfer to a food processor), carefully puree until smooth.
- Stir in kale and pepper, return to the stove and simmer until the kale is tender, about 8–10 minutes.
- Ladle soup into bowls and top with nutritional yeast (vegan) or Parmesan cheese, if desired.