For the peppers: Preheat a broiler. Arrange the peppers in a single layer on a heavy, rimmed baking sheet. Broil, turning the peppers every few minutes, until charred on all sides, 5 to 10 minutes. Put the peppers in a resealable plastic bag for 15 minutes. Gently scrape off the burnt skin, being careful not to tear the flesh. Lay each pepper on a cutting board.
Using a paring knife, remove a ½-inch-wide strip of flesh from the side of each pepper to create an opening. Chop the strips of pepper into ½-inch pieces to reserve for the filling. Using a small spoon, remove the seeds from inside each pepper.
In a medium saucepan, bring ¾ cup water to a boil over medium-high heat. Stir in the couscous and ½ teaspoon salt. Simmer for 1 minute. Remove the pan from the heat and cover. Let stand for 5 minutes. Uncover and fluff the couscous with a fork.
Position a rack in the center of the oven and preheat the oven to 400 degrees. Spray a 9- by 13-inch baking dish with vegetable oil cooking spray.
In a small nonstick skillet, heat the oil over medium-high heat. Add the shallot, garlic, remaining ½ teaspoon salt and the pepper. Cook until the shallots are soft, about 3 minutes.
In a large bowl, combine the couscous, shallot mixture, the reserved chopped bell pepper pieces, the raisins, almonds, olives, lime juice, maple syrup, and half of the cheese.