Colombian-Style Cloth-Wrapped Grilled Beef Tenderloin. Literally translated as "beef tenderloin in a towel," lomo al trapo is made by wrapping a big chunk of beef tenderloin in a thick crust of salt swaddled in a towel, tying it up, and throwing it directly on a fire until it's cooked. It's one of the easiest, most foolproof, primally delicious, and downright impressive. All it takes is three ingredients, a few basic kitchen supplies, and a fire. No pots, pans, or even a grill required.
- 1 1/2 to 2 pounds salt
- 6 to 8 sprigs oregano, rosemary, or thyme
- 1 center-cut trimmed beef tenderloin (2 to 2 1/2 pounds)
- 1 recipe ají or chimichurri, if desired
- Dip a clean dish towel in a bowl of cold water or run it briefly under a cold tap, then wring it thoroughly so it is just slightly damp. Lay it on your work surface, with the short edge parallel to the counter edge. Spread a layer of salt at least 1/2 inch thick on the towel, starting about 1 inch up from the leading edge and progressing back about 12 inches, leaving a 2-inch space on either side. Scatter with herbs and place beef directly on the salt on the edge closest to you.
- Carefully roll the beef up until it is completely surrounded in salt. Tuck the leading side of the towel into the roll, fold in the sides to form a neat package, then continue rolling until the beef is completely wrapped in the towel.
- Using butcher's twine, secure the package at 1- to 2-inch intervals, tying as tightly as possible.
- Light one chimney full of charcoal. When all the charcoal is lit and covered with gray ash, pour out and arrange the coals on one side of the charcoal grate.
- Place beef directly on coals. Partially cover grill and cook for 10 minutes. Flip beef and continue cooking until an instant-read thermometer inserted into the deepest part of the package registers 95°F for rare or 105°F for medium-rare. (I do not advise cooking for longer than that if you want juicy meat.) Transfer the whole package to a metal tray or pan and let rest until the core reaches 120°F for rare or 130°F for medium-rare, about 10 to 20 minutes.
- When ready to serve, carefully crack open the crust with the back of a knife, reserve some of the smoky salt for serving, and discard the burnt cloth and remaining salt. Use the back of your knife or a pastry brush to remove any excess salt. Slice tenderloin and serve with ají or chimichurri as desired.