Add all of the ingredients for the chimichurri sauce to a blender or food processor and blend until the herbs are finely chopped and it is evenly green. Pour half of the sauce into a re-sealable, gallon sized, zipper top bag. Add the chicken to the zipper top bag. Seal the bag, squeezing out as much air as possible and squish the bag around to evenly coat the chicken tenders with the chimichurri. Refrigerate for at least 20 minutes but up to 2 hours.