Place the squash, onion, potato, carrots, garlic, chickpeas, and the meat (if you are using it) into the crock pot. Pour the stock over. Pour on the spices. Give a good stir. Cook on low for 5-6 hours or on high for 3-4 hours. In the last 20 minutes before serving (for instance, while you are making your couscous), mix in the spinach.