Steps
1. Preheat the grill or a grill pan over medium-high heat.
2. Season the mackerel fillet with olive oil, salt, and pepper.
3. Grill the mackerel for about 5-7 minutes on each side, or until the fish is cooked through and has nice grill marks.
4. In a bowl, combine the diced mango, red onion, red chili, lime juice, salt, and pepper. Mix well to create the salsa.
5. Once the mackerel is done, plate it and top with the mango salsa.
6. Garnish with fresh cilantro and serve immediately.