Preheat a grill or grill pan and oil the grate. Rub the fist with the olive oil and season inside and out with salt and pepper. Grill the fish over moderately high heat, turning once, until the skin is crisp and charred and the flesh is flaky and just opaque, about 15 minutes. Transfer to a platter and sprinkle with flaky sea salt and garnish with cilantro leaves, scallions and thinly sliced jalapeño. Flake the fish with a fork and serve with lime wedges, corn tortillas and the Cantaloupe Pico De Gallo.