In a medium bowl, whisk together the lime juice, olive oil, minced garlic, chopped jalapeños, ground cumin, smoked paprika, salt, and pepper to create a marinade.
Place the chicken breasts in a large resealable plastic bag or a shallow dish, and pour the marinade over them, ensuring the chicken is fully coated. Seal the bag or cover the dish and refrigerate for at least 30 minutes, or up to 2 hours for more flavor.
Preheat your grill to medium-high heat.
Remove the chicken from the marinade, letting any excess drip off. Discard the leftover marinade.
Grill the chicken for about 6-7 minutes per side, or until the internal temperature reaches 165°F (75°C) and the chicken has nice grill marks.
Once cooked, remove the chicken from the grill and let it rest for 5 minutes to retain its juices.
Slice the chicken, garnish with fresh cilantro, and serve immediately.
Notes
For a spicier kick, leave some seeds in the jalapeños.