I have cooked meat -usually fish- and vegetables in a salt crust before, but not like this. I saw this Colombian dish on Kenji’s Food Lab and it immediately caught my attention. It is too cool, too old and new at the same time and just plain wild. Christmas dinner seemed like an excellent occasion for this. It is a luxurious cut of beef but also most of the attendees -Diana’s family- would be Colombian. So curious to try it out but not wanting to screw up Christmas eve dinner I made a trial run first to make sure. It was a good idea and made the second time I cooked it for a crowd much easier. The concept is pretty simple; wrap beef tenderloin in a salt crust encased in a towel (that’s the Trapo), throw it on a pile of hot coals until done, remove, crack the crust away, slice and enjoy. A few details are important to note though.
The middle of the tenderloin is the best part to use here. I bought whole tenderloins and trimmed them myself. I managed to get three semi-even cylindrical pieces and the rest of the meat went in the freezer for other uses. To wrap each one, I laid a cotton kitchen towel and covered it with about 1/2 inch of kosher salt and a scattering of herbs (thyme, marjoram, rosemary). This carefully gets wrapped around the trimmed beef tenderloin. It’s a bit tricky to do and needs some practice to make sure the salt does not clump in one area or falls off the sides. A quick confident roll is key. I tied he rolls with twine and they were ready to go on the charcoal.
When I say “on the charcoal” I literally mean that. Directly on hot fully ashed-up coals. It is impossible to tell how done the meat is in the salt cocoon. That salt gets hard very fast and that is what you want. It just makes it tricky to figure out when the meat is rare and to account for carry-over cooking. So, of course you need to use a thermometer. After 10 minutes on one side, I flip the meat over and started taking the temperature. I over shot a bit the first time and the meat that came up beautiful off the coals, but a little overcooked by the time it was sliced. To get the nice medium-rare final serving temperature, you need to shoot for about 92 F when you take it off the grill. Let the meat rest until it reaches 125 – 130 F and crack the salt crust open.
By now the towel is mostly burnt away and a few taps with the back of a knife is enough to reveal the amazing burnished and very savory beef. The smell is really phenomenal at this point and the whole spectacle is too much for any of the guests not to stand, stare and “oooh”.
I served this very simply and triditionally with boiled salted marble potatoes and a sharp chimichurri sauce (parsley, oregano, garlic, olive oil, vinegar). The potatoes were boiled with lots of salt until the water evaporates and the salt remains. This was another recipe from Kenji (and also a traditional Colombian preparation) but they did turn out a bit too salty so they need some work. By contrast the salt encrusted beef was delicious, perfectly seasoned and perfectly cooked. It really is a show-stopper of a roast.