To a small bowl, add the parsley, cilantro, onions, garlic, chili, oregano and basil. Add the oil, vinegar, salt and pepper and mix well to combine.
Allow the flavors to meld for 10 minutes.
Pour about ⅓ of the chimichurri sauce over the chicken and toss to completely coat. Reserve the remaining chimichurri to serve with the chicken; make sure it doesn't touch the raw meat.
Allow the chicken to marinate for 15-20 minutes.
Preheat a grill pan or your outside grill on medium-high heat. Add the chicken and cook for 6-8 minutes per side, or until fully cooked through.
Serve with the remaining chimichurri sauce and enjoy!
Notes
Use lean chicken breasts. If you prefer to use chicken thighs, you can use boneless chicken thighs instead.
Alternate source of protein could be shrimp or steaks
You may use an outdoor or indoor grill
Must use fresh parsley and fresh garlic
Do not overcook the chicken so it's not too dry and rubbery
If you can, do marinate the chicken unless you are in a rush you can skip marinating.
Store in a sealed container in the fridge for up to 3 days.