Heat the olive oil in a large soup pot over medium heat. Add the yellow onion, carrots, and celery. Cook for 7 to 8 minutes, stirring, until the onion softens.

Stir in the garlic and dried thyme. Cook for 1 minute, until fragrant.

Place approximately one-third of the cannellini beans in a bowl and mash with a potato masher, adding a splash of the measured low-sodium vegetable broth if needed.

Add the mashed and whole cannellini beans, remaining low-sodium vegetable broth, fine salt, and black pepper to the pot. Bring to a gentle boil, then reduce the heat and simmer uncovered for 10 minutes, until the carrots are tender.

Stir in the chopped kale. Simmer for 4 to 5 minutes, until the leaves are tender and bright green.

Remove from the heat and stir in the fresh lemon juice. Taste and adjust the fine salt if needed. Ladle into bowls and serve.