Heat the olive oil in a large heavy pot over medium heat.

Add the chopped onion, chopped carrots, chopped celery, chopped pancetta, and minced garlic. Sauté until the onion becomes translucent (about 10 minutes).

Add the chopped Swiss chard leaves and the cubed potato to the pot. Sauté for about 2 minutes more.

Add the diced tomatoes and the fresh rosemary sprig. Simmer until the Swiss chard is wilted and the tomatoes begin to break down (about 10 minutes).

While that’s simmering, in a blender or food processor combine ¾ cup of the drained cannellini beans with ¼ cup of the beef broth. Blend until almost smooth.

Add the pureed bean mixture to the pot, along with the remaining beef broth and the Parmesan rind. Bring back to a simmer and cook until the potato pieces are tender, stirring occasionally (about 15 minutes).

Stir in the remaining whole cannellini beans and the chopped parsley. Simmer for about 2 minutes more, until the beans are heated through and the soup has thickened a bit.

Remove and discard the Parmesan rind and the rosemary sprig (the leaves will have fallen off). Season the soup with salt and pepper to taste.

Ladle the soup into bowls and serve. For extra comfort, serve with rustic crusty bread to mop up the broth.