In a mixing bowl, combine the minced garlic, chopped jalapeños, lime zest, lime juice, olive oil, ground cumin, smoked paprika, salt, and pepper. Whisk the marinade until well blended.
Place the chicken breasts in a large resealable plastic bag or a shallow dish. Pour the marinade over the chicken, ensuring it is well coated. Seal the bag or cover the dish and marinate in the refrigerator for at least 30 minutes (up to 2 hours for greater flavor).
Preheat your grill (or oven) to medium-high heat. If using a grill, oil the grates lightly to prevent sticking.
Remove the chicken from the marinade, allowing excess marinade to drip off. Discard the leftover marinade.
Grill the chicken for approximately 6-7 minutes on each side (or until fully cooked and internal temperature reaches 165°F/75°C). If using an oven, bake at 375°F (190°C) for about 25-30 minutes.
Once cooked, remove the chicken from the grill/oven and let it rest for 5 minutes before slicing.
Garnish with fresh chopped cilantro before serving.