Combine rinsed rice, coconut milk, water, and salt in a medium saucepan. Bring to a boil over high heat, then reduce heat to low, cover tightly, and simmer for 15 minutes. Remove from heat and let stand, covered, for 10 minutes. Fluff with a fork before serving.

Pat chicken thighs completely dry with paper towels. Rub jerk seasoning evenly over all sides, pressing it into the meat. Let sit at room temperature while you make the salsa, or refrigerate up to 4 hours ahead.

Heat oil in a large skillet over medium-high heat until shimmering. Add chicken thighs in a single layer (work in batches if needed) and cook undisturbed for 5-6 minutes until deeply browned. Flip and cook 4-5 minutes more until cooked through and juices run clear. Transfer to a cutting board and let rest 5 minutes, then slice into strips.

While chicken cooks, combine diced mango, bell pepper, red onion, lime juice, cilantro, and salt in a bowl. Toss gently and taste - add more lime or salt if needed. Let sit at room temperature for flavors to meld, or refrigerate up to 2 hours.

Divide coconut rice among bowls. Top with sliced jerk chicken and a generous spoonful of mango salsa. Garnish with extra cilantro and serve immediately.