Pull your picanha out of the refrigerator 45 to 60 minutes before cook time and set it on a clean sheet pan. Using a sharp knife, score the fat cap in a crosshatch pattern with cuts about one inch apart - go deep enough to reach almost to the meat but do not cut through into it. This scoring allows the fat to render evenly, prevents the cap from curling up during the cook, and lets that salt get down into every part of the crust you are building.

Season aggressively. Hit the fat cap side with about half your coarse salt, pressing it firmly down into the scored cuts. Flip the steak and rub the meat side with a thin coat of avocado oil, then apply the remaining salt, all of the black pepper, and the garlic powder if you are using it. Let the seasoned picanha sit uncovered at room temperature for the full 45 minutes. You will see the salt pull a little moisture to the surface - that is exactly what you want for that crust.

Fire up the grill while the meat rests. Fill your chimney starter with high-quality hardwood charcoal - Brazilian hardwood charcoal is fantastic here if you can find it, but lump charcoal works great. Light the chimney and let it run until the coals are fully lit and glowing orange with a light ash coating, about 15 to 20 minutes. Dump the coals to one side of the kettle to create a two-zone fire. Your direct zone should be screaming hot - hold your hand five inches above the grate and you should only last one to two seconds. That is your searing zone sitting around 500 to 550 degrees Fahrenheit.

Start fat-cap-side down over the direct heat. Place the picanha fat-cap-side down directly over the coals and do not touch it for 4 to 5 minutes. You are rendering that fat, crisping the outside of the cap, and building a gorgeous golden-brown crust. Keep an eye on flare-ups - the dripping fat will cause flames, and that is fine in small bursts, but if it turns into a full bonfire, slide the steak slightly toward the indirect zone for 30 seconds to calm things down, then return it.

Sear the meat side. Flip the picanha using your long tongs and sear the meat side directly over the coals for another 3 to 4 minutes. You are looking for a deep mahogany-brown color across the entire surface. Do not press down on the meat - let the heat do the work. If you see areas that are not making contact with the grate, tilt and rotate the steak to ensure even color all the way across.

Move to indirect heat to finish. After searing both sides, slide the picanha to the indirect zone of your grill with the fat cap facing up. Close the lid, crack the vents to maintain around 300 to 325 degrees Fahrenheit in the indirect zone, and let the steak cook low and slow to reach your target internal temp. Insert your instant read thermometer into the thickest part of the meat - not into the fat cap - and start checking at the 15-minute mark. Pull the steak at 125 degrees Fahrenheit for rare, 130 degrees Fahrenheit for medium-rare, or 135 degrees Fahrenheit for medium.

While the steak finishes on indirect heat, make your chimichurri. Finely chop the fresh parsley and smashed garlic and combine them in a small bowl with the red wine vinegar, olive oil, red pepper flakes, and a pinch of salt and pepper. Stir well and let it sit so the flavors can come together. This bright, acidic sauce is the classic Brazilian complement to picanha and cuts right through the richness of that fat cap.

Rest the meat - this step is non-negotiable. Pull the picanha at your target internal temp and transfer it to a clean cutting board or sheet pan. Tent it loosely with foil and rest the meat for at least 10 minutes, preferably 15. The internal temp will climb another 3 to 5 degrees during rest. This resting period allows the muscle fibers to relax and redistribute the juices evenly throughout the steak. Cut into it too early and you will lose half those juices onto your cutting board.

Slice and serve. After resting, place the picanha fat-cap-side up on your cutting board. Slice it against the grain in pieces about half an inch to three-quarters of an inch thick. The grain on picanha runs in one direction across the rump cap, so orient your cuts perpendicular to those muscle fibers. Each slice should show a beautiful pink interior surrounded by a rendered, crispy fat cap edge. Arrange on a wooden board, drizzle with chimichurri, and get ready for compliments.