Salt-Crusted Beef Tenderloin

Make the roast beef

1. Preheat the oven to 250°F (121°C). Place a wire rack on a rimmed baking sheet. Heat a large, heavy, cast-iron skillet or Dutch oven over medium heat for 5 minutes. Yep, 5 minutes. Make certain the heat is on medium and no higher. Also make certain your hood fan is on.
2. Using your hands, rub the grapeseed oil over the beef to coat all sides and then sprinkle it evenly with black pepper. Brown the beef tenderloin, using tongs to turn it as necessary so it gets thoroughly browned on every side, including the ends. You want the meat to have a nice crust all around to create a barrier for the salt crust. It'll take at least 7 to 8 minutes to get a good sear. Transfer the tenderloin to the wire rack to cool.
3. In a bowl, mix the salt with some of the water to form what looks like bright white wet sand. Start with 1 1/4 cups water and, if necessary, add more water, a little at a time, to achieve a sand-like consistency that sticks to itself when you squeeze it in your hand. (If you're having a tricky time with the salt mixture adhering to itself, dump it back in the bowl, add an egg white, mix well, and try again.)
4. When the tenderloin is cool and mostly dry, spread a thin but solid and even layer of salt on the bottom of a small rimmed baking sheet or a smallish roasting pan with low sides. Place the tenderloin on the salt. Pack the remaining salt tightly and tidily around the tenderloin to create a solid coating, sorta like a cast on a broken leg. Where there are cracks in the crust, redistribute the salt to patch them. This should be an unfussy task! There is no such thing as perfect. (If you use a cut of meat that's larger than 1 1/2 pounds, you'll need more salt and water to encase it. Mix up a little more of the salt mixture so the beef is completely surrounded by salt.)
5. If you have an oven-safe instant thermometer, insert it through the salt into the beef. Place the salt-crusted beef and its pan in the oven and roast for 45 minutes. If the beef is the exact weight specified in this recipe, then 45 minutes at 250°F (121°C) will deliver medium-rare tenderloin. Otherwise, insert an instant thermometer straight into one of the short ends of the tenderloin directly into its center. The beef is ready to take out of the oven when it hits 125°F (52°C) in its center.

Make the bread crumb salsa (optional)

1. While the tenderloin is in the oven, place a small, deep-sided sauté pan over medium-high heat. The oil should be just deep enough to submerge the first tip of your index finger. Heat the oil. (Good olive oil is rarely recommended for frying. But the author really prefers the flavor it adds.) Have ready a stack of basket-style coffee filters or a brown paper bag next to the stovetop.
2. When the oil makes beautiful, veinous, streaking patterns in the pan, which will move faster as the oil gets hotter, drop in a crouton as a test. If it sizzles on contact, the oil is ready. Keep a careful watch on the oil, turning the temperature down as needed, as you do not want the oil to smoke.
3. Fry the croutons until golden brown. Using a slotted spoon, drain them on the coffee filters or brown paper bag. Let the oil cool.
4. While the oil cools, supreme the lemons. (See the video on how to supreme citrus just above the recipe.) Simply slice off both ends of each lemon to reveal some of the fruit beneath. Stand a lemon on one end. Starting at the top of the lemon, use the knife to slice away the peel and underlying white pith, following the curve of the fruit, and repeat, turning the lemon as needed, until all the peel and pith is removed. Hold the lemon over a bowl in one hand and, using the other hand, slide the knife blade alongside a membrane and then alongside the other membrane of that same segment, slicing all the way through to the center of the lemon. The lemon segment should fall away into the bowl without any stringy membrane attached. Repeat with the remaining segments, letting any juice drip into the bowl beneath. When you're done, squeeze the membranes to release any more juice and then toss the membranes in the compost. Repeat with the second lemon.
5. To the lemons and their juice add the zest, tomatoes, scallions, garlic, anchovies, and vinegar and toss well. Add the fried croutons and 1/3 cup of the cooled frying oil.
6. Rub the parsley leaves between your hands to release the grassy aroma and then toss them in the salsa. Sparingly season the salsa with salt and pepper to taste, keeping in mind that the beef will bring some saltiness to the plate.

Assemble the dish

1. Using a mallet or a wooden spoon, crack the salt crust on the tenderloin, dust away the granules of salt clinging to the beef with a clean, dry towel, and place the beef on a cutting board.
2. Slice the tenderloin, aiming for portions of 6 ounces. Arrange the slices on each plate, overlapping the slices slightly. If using the salsa, drizzle a generous spoonful of salsa over the meat, being careful to let the perfect wall-to-wall pink of the filet show through. If you wish, drizzle the beef with some of the remaining fry oil to finish. Do not season further. Serve immediately.