Heat the olive oil in a skillet over medium heat. Add the lamb chunks and brown them on all sides for about 5 minutes.
Add the diced onion, minced garlic, and chopped rosemary to the skillet. Cook for 3 minutes until the onion softens.
Transfer the lamb mixture to the slow cooker. Add the drained white beans, diced tomatoes, beef broth, salt, and black pepper.
Stir everything together, cover the slow cooker, and cook on low for 8 hours.
Serve the stew in bowls and top each portion with grated Parmesan cheese.