In a medium baking dish, whisk together lime juice and molasses. Add chicken and marinate at room temperature for 15 minutes, turning over halfway. Shake off and discard marinade. Season chicken with 1⁄4 tsp salt, 1/8 tsp pepper, cumin and coriander. Position oven rack about 6 inches below heating element and preheat broiler to high. Mist a grated broiler pan with cooking spray and place over a large foil-lined baking sheet. Arrange chicken on broiler pan and broil until no longer pink in thickest part and juices run clear, turning over halfway, about 12 to 14 minutes. (NOTE: Watch carefully to prevent burning; switch to baking in a 350°F to 400°F oven if molasses appears to be burning.)Meanwhile, to a medium saucepot, add farro, 1⁄4 tsp salt and 2 cups water; cover and bring to a boil. Reduce heat to low, cover and simmer until farro is tender and liquid is absorbed, about 30 minutes. Drain in a colander and transfer farro to a large bowl. Stir in lime zest, remaining 1⁄4 tsp salt, remaining 1/8 tsp pepper, cilantro, mint and pomegranate seeds (if using). Serve chicken with farro.