1Heat gas or charcoal grill. In shallow bowl, mix taco seasoning mix and oregano. Brush chicken with oil; sprinkle with taco seasoning mixture.
2Place chicken on grill over medium heat. Cover grill; cook 10 to 15 minutes, turning once, until juice of chicken is clear when center of thickest part is cut (170°F).
3Meanwhile, in small microwavable bowl, mix barbecue sauce, chili sauce and cumin. Cover; microwave on High 30 to 60 seconds or until hot. Serve sauce over chicken.