Add the beef stew meat to the slow cooker first.
Layer the diced onion, minced garlic, and drained cannellini beans on top of the beef.
Pour the diced tomatoes and beef broth over the other ingredients.
Sprinkle in the rosemary, thyme, oregano, salt, and pepper, then stir once to combine.
Cover the slow cooker and cook on low for 8 hours.
Stir the stew gently before serving to distribute the beans and meat.