Add one can of rinsed beans to a food processor along with 1/2 cup broth. Process until smooth, then set aside.

Heat 1 Tbsp olive oil in a large pot over medium heat. Add onion, carrots, and celery; sauté for 5 minutes. Add garlic and sauté for 1 minute longer.

Pour in remaining 4 cups broth, add parmesan rind and rosemary, and season with salt and pepper to taste. Bring to a simmer over medium-high heat, then reduce heat to medium-low. Cover and simmer for 10 minutes.

Add remaining 2 cans of beans (drained and rinsed) and the bean puree mixture; continue to simmer for 5 minutes, covered.

Add kale and continue to simmer, covered, until softened, about 5 minutes longer.

Remove parmesan rind. Stir in parsley, remaining 3 Tbsp olive oil, and lemon juice.

Garnish each serving with grated parmesan.