In a small bowl or ramekin, prepare the marinade by adding the lime juice, extra virgin olive oil, cumin, red pepper flakes, salt, pepper, and 1 slice of jalapeño.
Place the chicken breasts and marinade in a plastic bag. Put in the refrigerator for a minimum of 2 hours to marinate (overnight is ideal).
Remove chicken and marinade from the refrigerator 20 minutes before cooking to bring to room temperature prior to cooking.
Heat a skillet to medium heat. Once the skillet is hot, place the chicken on the skillet, and pour the marinade over it. Cook for 7 minutes until the chicken begins to brown on the bottom, then flip the chicken with a spatula and cook another 7 minutes on the other side, or until fully cooked through.
Remove the chicken from the skillet, serve immediately with sliced jalapeños, and garnish with cilantro.