Heat the olive oil in a large Dutch oven over medium-high heat. Season the lamb with salt and pepper, then brown it in batches until all pieces are seared on all sides. Remove the lamb and set it aside.
Add the onion to the pot and cook for 4 minutes until softened. Stir in the garlic, cumin, and cinnamon and cook for 1 minute more.
Pour in the Syrah wine and scrape up any browned bits from the bottom. Let it simmer for 2 minutes to reduce slightly.
Return the lamb to the pot along with the beef broth and harissa paste. Bring the mixture to a boil, then reduce the heat to low, cover, and simmer for 1 hour.
Add the eggplant cubes and chopped dates. Continue simmering uncovered for 30 minutes until the eggplant is tender and the lamb is fall-apart soft. Taste and adjust salt and pepper if needed.
Ladle the stew into bowls and top with fresh cilantro before serving.