Lets start by making the mojo. Add all of the ingredients to a food processor and blend.
Cut the chicken breast in half, and lay on a cutting board one by one. Place saran wrap if you have some over the breast(it's ok if you dont), one by one, and pound it with a kitchen hammer or a pan, to make it about a quarter inch thick.
Place your chicken in a bowl or dish and pour all of the marinade on it. Toss well and let it sit for 30 minutes
To grill the chicken, heat some oil over medium-high heat. Once the oil is hot, place the chicken breast in. Cook each side for about three to four minutes, until the chicken is slightly browned on each side. It should be a nice golden brown crust.
If you want to top it with onions, slice your white onion thin strips and add it the same pan you used for the chicken. Saute for about 5 minutes.
Squeeze some lime over the chicken, serve and enjoy. Traditionally served with white rice, beans and avocado