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 and set aside to allow flavors to meld.
03 - Lightly coat a 9x13-inch baking dish with olive oil, ensuring an even layer across the bottom to prevent sticking.
04 - Arrange the chicken breasts in the prepared baking dish. Sprinkle both sides of each breast evenly with ground cumin, chili powder, and paprika, pressing the spices gently into the meat.
05 - Spoon the prepared salsa fresca generously and evenly over each seasoned chicken breast, ensuring full coverage.
06 - Distribute the shredded Monterey Jack or mozzarella cheese evenly over each chicken breast, covering the salsa layer completely.
07 - Bake uncovered for 25 to 30 minutes, until the chicken reaches an internal temperature of 165°F and the cheese is melted, golden, and bubbly.
08 - Remove from the oven and let rest for 5 minutes to allow juices to redistribute. Garnish with additional fresh cilantro if desired and serve immediately.