Heat some oil in a roasting tray and then add the onions and fry for about 5 mins until just softened. While you’re frying, add the saffron strands to the stock if using, so the flavour and colour infuses. (If you are making the Fragrant chicken too (see 'Goes well with') use the same pan to add flavour to this dish and leave the juices in there, but you can tip out some of the chicken fat if you like).
Tip the chilli into the tray, fry for 1 min more, then take off the heat. Add the couscous and stock, then cover with cling film for 10 mins. Once the couscous has absorbed all the stock, quickly chop the coriander (if you chop it too soon it will start to wilt), then fork it through the couscous with the almonds, dates and lemon juice and serve straight away. To serve cold, leave to cool, then add the chopped coriander just before eating.