If you prefer a nuttier flavor, use bulgur instead of couscous in the filling.
Heat grill to medium-high. Drizzle peppers with 2 tablespoons oil. Grill, turning once, until charred in spots, 10 to 12 minutes.
Meanwhile, combine 3 tablespoons oil, shallots, and a pinch of salt in a large cast-iron skillet; place on grill. Cook, stirring often, until shallots soften, 5 minutes. Add tomato and raisins; cook, stirring, 1 minute. Add couscous and 1 1/2 cups water; season with salt and ground pepper. Simmer, stirring, until water has evaporated, about 4 minutes; remove from heat. Transfer mixture to a bowl; let cool slightly, then stir in mint, cheese, and egg. Season insides of peppers with salt and ground pepper; place in skillet. Divide fill- ing among peppers; return skillet to grill. Cover and cook until filling binds, 5 minutes. Serve, drizzled with oil, alongside greens.