Heat the olive oil in a large heavy-bottomed pot or traditional tagine over medium-high heat.
Add the diced lamb shoulder in batches, browning the pieces on all sides. Remove the browned lamb and set aside on a plate.
In the same pot, add the chopped red onion and sauté until softened, about 5 minutes. Stir in the minced garlic, ground ginger, cumin, ground cinnamon, and turmeric, cooking for 1 minute until fragrant.
Return the browned lamb and any resting juices to the pot. Add the broth, dried apricots, chopped dates, prunes, and the cinnamon stick. Bring the mixture to a gentle boil.
Reduce the heat to low, cover tightly with a lid, and simmer gently for 1.5 to 2 hours, or until the lamb is highly tender and the sauce has thickened.
While the tagine is in its final minutes of cooking, prepare the couscous according to the package instructions.
Remove the cinnamon stick from the stew. Garnish the tagine with freshly chopped parsley and mint, and serve warm over the prepared couscous.