Preheat the oven to 375°F (190°C) and lightly grease a 9x13 inch ceramic or glass baking dish.
In a small mixing bowl, emulsify the olive oil with the taco seasoning, garlic powder, salt, and black pepper.
Apply the spice paste evenly to all surfaces of the chicken breasts and arrange them in a single layer in the baking dish.
In a separate non-reactive bowl, combine the diced tomatoes, red onion, jalapeño, cilantro, and lime juice; toss thoroughly to incorporate the salsa fresca.
Distribute the salsa fresca evenly over the top of each chicken breast, ensuring full surface coverage.
Evenly distribute the shredded Monterey Jack cheese over the salsa layer.
Bake uncovered in the center rack for 25 to 30 minutes, monitoring for an internal temperature of 165°F (74°C) using an instant-read thermometer.
Remove from heat and allow the protein to rest for 5 minutes before service to facilitate juice redistribution.