Place the olive oil, onion, celery, and carrots in a soup pot and cook over medium heat until tender, about 7 minutes.
Rinse and drain the canned white beans and add them to the pot. Add the broth, potatoes, rosemary, salt and pepper and raise the heat to high. Bring to a boil.
Reduce the heat to a simmer and cook for 20 minutes. Use a potato masher or immersion blender to partially puree the soup. Add more salt and pepper if desired.
Serve with bread or crackers.
Notes
Store leftover soup in the refrigerator. Use within 4-5 days.