I lined my colander with cheesecloth since it has large holes that the couscous could fall through.
I made 1 cup of dried couscous. The couscous expands a lot when it is steamed--we only ate about half, though its good that I made this much, since we will eat the extra tomorrow with the leftover half of the chicken with preserved lemons.
Note: Make sure that you put lots of water in your steamer--it is easy to boil it dry. I though I had a bunch of water, but in the second steaming, I actually managed to boil away all my water, so next time I recommend adding a bit more water to the pot before the second steaming.
Note: In step 3, the first time I made this I added 1 cup water and 1/2 tsp salt for a couscous made with 1 cup dried couscous. The second time I made this I added 1 cup water and 3/4 tsp salt for the same amount of dried couscous. I think the couscous is best with 3/4 tsp salt (though if you are serving it with extremely salty food, you may want to use less salt).
The couscous, part way through cooking