Grilled Vegetarian Stuffed Peppers

Name: Grilled Vegetarian Stuffed Peppers
Ingredients: 4 assorted bell peppers (2 pounds total), halved and seeded; 5 tablespoons extra-virgin olive oil, plus more for drizzling; 2 shallots, halved and thinly sliced (1 cup); Kosher salt and freshly ground pepper; 1 large tomato (8 ounces), cored and chopped (1 ⅓ cups); ⅓ cup golden raisins; 1 cup plain couscous; 1 cup chopped fresh mint or parsley, or a combination; 1 cup crumbled feta (from a 4-ounce block); 1 large egg, lightly beaten; Mixed greens, for serving