What exactly is couscous?
Couscous is a coarsely ground pasta made from semolina, a type of wheat.
A staple of the North African Maghreb, couscous comes in instant and non-instant varieties.
Like macaroni and spaghetti, couscous is made from semolina flour, but rather than mixing the semolina with a prescribed amount of water and/or egg into a dough, couscous is made by rubbing the semolina between moistened hands until the flour combines with just enough water to form hundreds of tiny grains. Obviously the process takes a light touch, lest the grains combine into a gooey mass, but once learned it is one of the simplest forms of making pasta and one that is practiced in villages all around the Mediterranean basin.
After the couscous grains are formed they are dried and steamed over a stew, usually made from lamb, in a special pot called a couscoussière. Steaming couscous is an involved operation, requiring sealing the top of the couscoussière to its bottom with rags dipped in flour paste, and then interrupting the steaming several times to rub the softening couscous grains to insure that they remain separate.
Fortunately it is no longer necessary to go through all that labor, due to the broad availability of instant couscous. This product has already been steamed and then dried again before it is packaged. It needs only to be soaked in boiling water until it swells, a process that takes about 10 minutes.
Couscous doesn't have a lot of flavor on its own, but it works well as a base for vegetable or meat dishes. It also mixes beautifully into salads and can be flavored with herbs like coriander, basil or mint, or even studded with fruit like raisins or apricots. It's a very neutral -- and nutritious -- base for all sorts of dishes.
Reference: A really simple way to make couscous (Cookthink)