Heat the olive oil in a large pot over medium heat. Add the diced onion and cook for 4 minutes until it softens.
Stir in the minced garlic and cook for 1 minute until fragrant.
Add the drained cannellini beans, vegetable broth, diced tomatoes, dried rosemary, salt, and black pepper. Bring the mixture to a simmer.
Reduce the heat to low and let it cook for 15 minutes to blend the flavors.
Stir in the chopped kale and simmer for 5 more minutes until the leaves wilt.
Ladle the soup into bowls and top each serving with grated parmesan cheese.