Combine all the marinade elements in a bowl and mix well, setting aside 1/4 cup separately.
Place the chicken and remaining marinade inside a large resealable plastic bag, then refrigerate for 3 to 4 hours or overnight.
Heat the reserved marinade in a small pot over medium heat until it thickens slightly, about 3 to 5 minutes.
Preheat your grill to medium-high heat, around 375 to 400 degrees Fahrenheit.
Season both sides of the chicken with salt and pepper.
Grill the chicken for approximately 6 to 8 minutes per side depending on thickness, basting with the thickened marinade often.
For the salsa, combine diced tomatoes, mango, jalapeño, red onion, bell peppers, olive oil, lime juice, cilantro, and salt and pepper in a blender and pulse until just combined.
Chill the salsa for at least 1 hour before serving.
Serve the grilled chicken topped with the chilled mango salsa for a lively and flavorful meal.