In a small bowl, combine the cucumber, mango, red onion, serrano pepper, 2 tablespoons lime juice, 1/8 teaspoon salt and dash of pepper. In another small bowl, combine the yogurt, ginger, curry powder, remaining lime juice, and remaining salt and pepper., In a large nonstick skillet, heat oil over medium-high heat. Sprinkle chicken with curry, salt and pepper. Cook chicken until no longer pink, 6-8 minutes. Serve in naan halves with mango slaw, yogurt sauce and mint. Garnish with lime wedges.