Heat the oil in a large casserole or tagine with a lid over medium heat. Add the onions and cook until soft, about 6-8 minutes.
Add the garlic, ginger and tomato purée; cook for a minute or two until fragrant. Add the ras el hanout and cook for another 2 minutes. Add the chickpeas, squash, sweet potatoes, chopped parsley, coriander, mint and dried apricots and mix well to coat. Pour in 1 litre of the stock and the lemon juice and bring to a gentle simmer. Cook partially covered over low heat for about 45 minutes until the vegetables are tender.
Meanwhile, put the remaining 500 ml of stock into a pan and bring to the boil. Turn off the heat and add in the couscous. Cover with foil or a tea towel and allow to rest for 10-15 minutes. The couscous will absorb all the liquid and cook in its own steam. Once rested, add a knob of butter and fluff gently with a fork. You can at this stage add more flavour to your couscous – spices, chopped vine tomatoes, olives, mint, coriander etc.
To serve, put the couscous into bowls and spoon the vegetable tagine on top. Garnish with additional chopped parsley and coriander, plus some pomegranate seeds.