Step 1 Place lamb pieces into a clean, disposable plastic sandwich bag. Combine flour, cumin, coriander and paprika and add to the bag. Twist bag closed and shake to coat the lamb.
Step 2 Place a large heavy-based frypan over high heat. Spray with oil and add lamb. Cook for 3–4 minutes, or until golden brown all over. Remove lamb from pan and place in slow cooker. Re-spray pan with oil and add onion and carrot. Cook for 3–5 minutes, or until onion is translucent. Add onion and carrot to slow cooker.
Step 3 Top lamb, carrot and onion with tomatoes, grated ginger, cinnamon quills and beef stock. Stir briefly to evenly distribute ingredients. Cover with the lid, then cook on the low setting of your slow cooker (see tips) for 7–8 hours.
Step 4 Carefully remove lid. Add pumpkin and dates. Cook for a further 30 minutes, or until pumpkin is soft. Meanwhile, finely shred coriander leaves and combine with orange zest and garlic in a small bowl. Stir through olives and pistachios.
Step 5 Boil 3/4 cup of water and pour over couscous in a bowl. Allow to sit for a minute and then fluff grains with a fork.
Step 6 When pumpkin is soft, turn off slow cooker and season to taste with pepper. Serve tagine with couscous and gremolata.