Prepare the brine by mixing the water and pickling salt until the salt is completely dissolved; submerge the chicken thighs in the rbine for 30 minutes, then remove and drain.
Add the remaining ingredients to a food processor and blend until finely chopped.
Preheat the BBQ to 400°F, then place the chicken thighs on the grill.
Brush the thighs with chimichurri and turn them every 15 minutes.
Cook the thighs until they reach 74°C, then finish by brushing them one last time with chimichurri.