This is a great recipe for crowds - but regarding the Couscous cooking; its a tradition but completely unnecessary for the results given that the Couscous you buy is processed. I saw the women in the kitchen in Algers rubbing the flour into the Couscous by hand in 1965; that was the time to cook the Couscous 3 times in a Couscousier; today all Couscous sold outside North Africa is processed and proceeding as described on the box - saturating with liquid and heating the Couscous - produces the same results and saves a LOT of time and effort. And you don't need the special pot, which is expensive and hard to store anywhere.
(see also Roden, Claudia: The book of Jewish Food. - New York: Knopf, 1998. p 490f.)

Proceed with the meat and vegetables as described.