Butterfly breasts into pieces about 1/2 inch thick. Rub with oil then squeeze on lime juice. Season with ground cumin and salt.
Grill on stove top grill pan or outdoor grill 5-6 minutes per side. Set aside and keep warm.
Roast peppers until blackened on stove top or under broiler, let steam, peel, remove seeds and chop. Slice unpeeled mango and rub cut side with oil. Sprinkle with chili powder. Grill cut side down for 3-5 minutes. Let cool and cut into cubes removing peel.
Toss grilled pepper and mango with tomato, onion, cilantro and jalapeno. Squeeze lime juice over salsa and mix. Season the salsa to taste with salt and pepper.
Place grilled chicken in a baking dish and top with salsa and cheese. Place under broiler until cheese melts.