Combine the ingredients for the chicken marinade in a freezer bag. Place the chicken in the bag, press the air out, seal and massage the mixture into the chicken. Marinate for at least an hour or overnight.
Heat grill to medium-high heat. Oil the grates, then place the marinated chicken on the grill. Grill for 4-6 minutes then flip and grill another 4-6 minutes or until the internal temperature reaches 160-165°. Let the chicken rest for at least 5 minutes before slicing it.
In a medium sized bowl add the avocado, tomatoes and lime juice and season with salt and pepper. Taste for seasoning then serve alongside or on top of the grilled chicken. Garnish with cilantro if desired.
Notes
Cilantro Chimichurri is not included in nutritional info.