Add the beef stew meat to the slow cooker.
Stir in the harissa paste, chopped onion, minced garlic, sliced carrots, and cubed potatoes.
Pour in the diced tomatoes and beef broth.
Add the ground cumin along with salt and black pepper.
Cover and cook on low for 8 hours until the beef is tender.
Stir the stew before serving and top each bowl with fresh cilantro.