1Combine the tequila, lime juice, orange juice, chili powder, jalapeno pepper, garlic, salt, and pepper in a large bowl.
2Add the chicken breasts. Refrigerate several house.
3Heat a grill with coals and brush the rack with oil to prevent the chicken from sticking.
4Remove the chicken breasts from marinade, sprinkle well with salt and pepper, and grill them skin-side down for about 5 minutes, until nicely browned.
5Turn the chicken and cook for another 10 minutes, until just cooked through.
6Remove from the grill to a plate.
7Cover tightly and allow to rest for 5 minutes. Serve hot or at room temperature.