Thank you to Second City Prime for the picanha that inspired this recipe.
Set your EGG up for indirect cooking with the convEGGtor at 325°F/163°C.
Using a sharp knife, cut the fat layer in a cross-hatch pattern without cutting the meat. Season with salt and Big Green Egg Classic Steakhouse Seasoning. Place the picanha on the cooking grid and cook for about 40 minutes, or until the internal temperature reaches 115°F. Remove from the EGG and let rest for about 10 minutes.
Remove the convEGGtor and set your EGG for direct cooking at 500°F/260°C.
Place the picanha back on the grid and sear for one minute on each side. Remove from the EGG once the internal temperature reaches 125°F. Serve with the sauce on the side.
While the picanha is cooking, mix together all the ingredients for the chimichurri sauce and refrigerate.