Pat dry the chicken breasts with paper towels.
In a bowl, whisk together lime juice, olive oil, garlic, cumin, chili powder, salt, and pepper until well blended.
Place chicken in a resealable bag or dish and pour marinade over it. Seal and refrigerate for at least 1 hour or overnight for best flavor.
Preheat grill or oven to medium-high heat (400°F). Remove chicken from marinade and discard any leftover marinade.
Grill each breast for about 6-7 minutes per side until fully cooked (internal temperature of 165°F). If baking, cook until done.
Serve garnished with fresh cilantro or lime wedges.
