Add all of the ingredients except the oil and vinegar into a large
bowl. Toss well to make sure that the salt is spread evenly
around the ingredients. Allow the mixture to rest for 30 minutes.
Next add the vinegar and water. Mix well. Allow to rest for
another 30 minutes.
Finally, add the oil and mix well. Make sure that the liquids cover
the rest of the ingredients. If not, add equal parts of oil, water,
and vinegar until they are covered at least by a quarter of an
inch. Transfer to a non-reactive clean bowl or jar that can be
covered. Make sure to cover well. Place in the refrigerator to
allow the flavors to blend overnight.
For best results, prepare the chimichurri at least 2 or 3 days
ahead of time. If refrigerated, allow sauce to sit at room
temperature for at least an hour or until the oil, if congealed,
thins out before serving.
The Boiling Liquid Method: Many in Argentina like to add an extra step to their chimichurri preparation that includes boiling the water and salt together, and immediately pouring the mixture over the rest of the ingredients before the oil is added.
This helps to tame the pungency of the garlic and parsley, thus creating a milder and smoother chimichurri. This method also works very well if you are short for time and need a well-balanced chimichurri, yet do not have the time to let it sit for a day or more before serving.