Remove the flesh from the preserved lemon and thinly slice the lemon rind.
Use flesh for another purpose.
Heat 2 tbsp oil in a large pan or tagine on medium heat.
Add onion, ginger, chilli powder, cumin and cinnamon and saute for 2 minutes. Add all the vegetables, except zucchini and tomato, and stir until they are well coated and start to soften.
Mix in preserved lemon rind, tomatoes, stock, pears and prunes. Cover and cook for 10 minutes.
Add zucchini and cook uncovered for a further 5-7 minutes or until vegetables are tender.
Remove the cinnamon stick, and stir in parsley and saffron flavored water.
Put couscous into another pan with 2 tbsp oil and 2 cups boiling water and let it stand until all the water is absorbed.
Fluff couscous with a fork and serve around the outside of the tagine or on a platter, with the vegetables in the center.
Sprinkle with toasted pistachios or almonds.