Set a large soup pot on the stove over medium heat. Add the olive oil and let it warm for about 30 seconds.

Add the onion, carrots, and celery to the pot. Stir to coat them in the oil.

Cook the vegetables for 6 to 8 minutes, stirring now and then, until the onion looks soft and the carrots have started to lose their raw edge.

Add the garlic and rosemary to the pot. Cook for 1 minute, stirring, until they smell fragrant.

Add the tomato paste to the pot. Stir it into the vegetables for 1 to 2 minutes, until it looks a little darker and sticks lightly to the bottom.

Pour the chicken broth into the pot. Stir well and scrape the bottom of the pot with a wooden spoon so any browned bits mix into the broth.

Add 1 can of the cannellini beans to the pot. Keep the second can of beans aside for later.

Raise the heat to high and bring the soup to a boil.

Once the broth is boiling, use a potato masher or the back of a sturdy spoon to crush many of the beans right in the pot. The broth should look a little thicker and slightly cloudy.

Add the second can of cannellini beans to the pot. Stir them into the broth.

Add the shredded chicken to the pot. Stir until the chicken is spread through the soup.

Bring the soup back to a gentle boil over medium-high heat. The surface should bubble steadily but not violently.