Preheat the oven to 375ºF. Pat the chicken thighs as dry as possible and cut into bite-sized pieces, about 1 inch.
In a large bowl, toss the chicken with the olive oil and taco seasoning until well combined. Spread the chicken out in a 9x13 glass or ceramic baking dish.
In another bowl, combine the tomatoes, jalapeño, onion, cilantro, lime juice, and garlic. Toss to combine and season to taste with salt and pepper. Use a slotted spoon to spread the salsa over the chicken, leaving as much liquid in the bowl as possible.
Sprinkle the cheese overtop the salsa and bake for 25 to 30 minutes, or until the chicken registers 165ºF on an instant read thermometer. Remove and let cool 5 minutes before serving.