Preheat the oven to 400°F and line a sheet pan with parchment paper.
Blend the aromatics. Add the onion and garlic to a food processor and blend on high for about 2 minutes, scraping down the sides halfway through, until finely minced.
Mix the meat. In a medium bowl, add the ground beef or lamb, spices, and the blended onion mixture. Use your hands to mix thoroughly until the meat is fully seasoned and cohesive. Divide into 5 equal oval portions.
Roll the meat thin. Place one oval on a sheet of parchment, then place another piece on top. Gently flatten with your hand, then roll with a rolling pin or wine bottle until thin but not paper-thin.
Wrap and transfer. Remove the top parchment (reserve to reuse) and roll up the bottom parchment around the meat to form a log. Place on the prepared sheet pan. Repeat with the remaining meat portions.
Bake. - For juicy, soft meat: bake for 20 minutes. Allow to cool slightly, then unroll the meat back on to the sheet tray to soak in the juices.- For a crisp, slightly charred finish: bake 15–17 minutes, then unwrap, spread evenly, and broil 2–3 minutes, watching closely to avoid burning. Serve and enjoy. Pair with lavash, tahini, fresh vegetables, or serve on top of salad with French fries on the side.