Put couscous, salt, and pepper in a large bowl. Add oil, and stir with fork to coat evenly.
Bring 2 1/2 cups water to a boil; stir one-third into the couscous. Cover remaining water to keep it hot.
Press couscous gently with the back of the fork. Cover with plastic wrap; let stand for 3 minutes. Repeat with remaining water in two additions.
Break up any clumps with a fork or your fingers.