In a bowl, whisk together tequila, lime juice, minced garlic, olive oil, chili powder, cumin, salt, and pepper to create the marinade.
Place chicken breasts in a resealable bag or shallow dish. Pour the marinade over the chicken, ensuring it is fully coated. Marinate in the refrigerator for at least 30 minutes, or up to 2 hours.
Preheat grill or a grill pan over medium-high heat.
Remove chicken from marinade, discarding the excess marinade. Grill chicken for about 6-8 minutes per side, or until cooked through and internal temperature reaches 165°F (74°C).
Let chicken rest for a few minutes before slicing and serving.
Notes
Serve with rice, beans, or a fresh salad for a complete meal. Garnish with fresh cilantro and lime wedges.