Cut 600 g of the salmon fillet into 5 cm pieces and set aside. Heat a tablespoon of oil in a large, wide pan with a lid, over a medium heat. Add the onion and garlic and cook for 10 minutes or until the onion and garlic soften. Add the cumin, paprika, ground coriander and turmeric, stir well and cook for 1 minute. Add in the cinnamon stick, tomatoes, courgette and water and cook for 10 minutes. Then add the lemon zest, reserving the juice for the couscous, and half the chopped coriander. Taste and season with salt and pepper. Season the smoked salmon and then place it in a single layer over mixture in pan. Cover and cook for 5 minutes.