Place all the Chimichurri sauce ingredients into the food processor. Pulse until all ingredients are chopped and well combined. Adjust consistency with more olive oil for a looser sauce. Cover and refrigerate until ready to use.
Submerge steak in Sweetwater Spice Tres Chiles bath. Let sit one hour for every pound of meat. Preheat cooker to 475°F. Grill about 2 to 3 minutes each side, until internal temperature reaches 125°F. Let rest ten minutes. Slice thin. Serve with hatch chimichurri sauce on the side.