In a bowl, combine the minced garlic, cumin, paprika, oregano, lime juice, olive oil, salt, and pepper to create a marinade.
Place the chicken breasts in a resealable plastic bag or a shallow dish, and pour the marinade over them. Make sure the chicken is evenly coated. Seal the bag or cover the dish and marinate for at least 30 minutes in the refrigerator, or up to 2 hours for maximum flavor.
Preheat a griddle or large skillet over medium-high heat. Add a little olive oil if needed to prevent sticking.
While the griddle is heating, take the marinated chicken out of the refrigerator.
Cook the chicken on the preheated griddle for about 6-7 minutes on each side or until browned and cooked through (internal temperature should reach 165°F/75°C).
In the last few minutes of cooking the chicken, add the sliced bell peppers and red onion to the griddle and sauté until they are tender and slightly charred.
Remove the chicken and vegetables from the griddle and let the chicken rest for a few minutes before slicing.
Serve the sliced chicken topped with sautéed peppers and onions. Garnish with fresh cilantro.
Notes
For best flavor, marinate the chicken for up to 2 hours.