Toss the corn with olive oil. Grill it until it is lightly charred all over, about 5-7 minutes.
Then grill the lemon halves for 1-2 minutes, cut side down.
Warm oil in a pot over medium heat. Toast the couscous until it is golden.
Pour in the water, bring to a boil, reduce heat to low, cover and simmer until the couscous is tender, about 10 minutes.