01 - Preheat oven to 400°F. Position the rack in the center of the oven.
02 - In a mixing bowl, combine diced tomatoes, red onion, cilantro, minced jalapeño, garlic, lime juice, salt, and black pepper. Toss gently until well incorporated, then set aside to allow flavors to meld.
03 - Lightly coat a 9x13-inch baking dish with olive oil to prevent sticking.
04 - Arrange the chicken breasts in the prepared baking dish. Evenly season both sides of each breast with ground cumin, chili powder, and paprika, pressing the spices gently into the meat.
05 - Spoon the salsa fresca mixture evenly over each seasoned chicken breast, ensuring full coverage.
06 - Generously top each chicken breast with shredded Monterey Jack or mozzarella cheese, spreading it over the salsa layer.
07 - Bake uncovered for 25 to 30 minutes, until the chicken reaches an internal temperature of 165°F and the cheese is golden and bubbling.
08 - Remove from the oven and let the chicken rest for 5 minutes before serving. Garnish with additional fresh cilantro if desired.