02Stir in the cumin, turmeric, cinnamon, coriander, cayenne and paprika.
03Continue stirring over medium heat for 2-3 minutes, then add vegetable broth, tomato puree and currants.
04Simmer the sauce for 10 minutes.
05Remove the sauce from heat and stir in fresh lemon (or lime) juice to your taste.
06If not using immediately and planning to reheat before serving, wait to add citrus juice at the last minute.
07To cook the couscous, heat the broth, water, butter and salt together in a medium skillet till the liquid boils.
08Reduce to a simmer, add the couscous, cover the skillet tightly and leave on the lowest heat for 5 minutes.
09Remove the pan from the heat an leave it covered for another couple of minutes before fluffing with a fork.
10(If using instant couscous, check package directions - you may not need to keep it on heat after boiling, but just cover and wait till liquid is absorbed - just see if liquid amounts match what is mentioned on the package).