Heat butter or ghee and olive oil in a large Dutch oven set over medium-high heat. Once hot, add the onion and garlic and sauté until tender and fragrant, about 4-5 minutes. Add the ras el hanout, turmeric, saffron (if using), salt, pepper, and stock; mix well.
Stir in the greens in batches, adding the next batch as the one prior wilts down. Cover and cook on low until tender, about 15-20 minutes.
Meanwhile, in a small pot, combine figs, ground cinnamon, and cinnamon stick and cover with water. Cook, uncovered, on medium-high heat until reduced by half, about 15 minutes. Add the honey and cook on low until the sauce becomes syrupy, about 5-10 more minutes.
Stir into the cooked greens and mix well. Serve hot topped with toasted walnuts.