BEEF WITH HORSERADISH-BEET AIOLI

Steps:

• Prepare the beef: Pat the beef dry and season all over with salt, pepper, lemon zest and grated garlic. Cover with plastic wrap and refrigerate at least 1 hour or overnight.
• Prepare the fresh horseradish and beets: In a food processor fitted with the grating blade, grate horseradish and beet. Replace the grating blade with the food processor chopping blade. Add vinegar, sugar and salt. Process until mixture is finely chopped, stopping occasionally to scrape down the sides of the bowl, 2 to 3 minutes.
• Prepare the aioli: In a medium bowl, whisk together egg, egg yolk, lemon juice and salt. Whisking constantly, add oil in a thin, steady stream until fully incorporated. (Or do this in the blender if you prefer.) Aioli should be emulsified, but somewhat loose. Stir in 2 to 4 tablespoons horseradish mixture, to taste; reserve remaining horseradish mixture and serve alongside aioli and beef. Chill aioli until needed; it will keep for up to 5 days.
• Remove beef from refrigerator. If needed, fold the thin end of the meat over itself so the meat becomes an evenly thick log, then tie ends with kitchen twine. (Skip this step if the meat is already an evenly thick log.)
• Bundle three leek halves together with kitchen twine, securing them in at least two places so that the leeks don't slip out. Repeat with remaining leek halves.
• Heat oil over medium-high heat in the bottom of a wide Dutch oven. Add beef and brown well on all sides, about 10 minutes. Transfer meat to a platter. Stir in wine and cook, scraping up any browned bits from bottom of pan, until reduced by half, about 3 minutes.
• Add leeks, root vegetables, garlic and stock to the pot. Tie thyme branches together with twine and drop into the pot. Stir in bay leaf. Bring mixture to a simmer.
• Add meat and any juices on the plate and cook, partly covered, at a gentle simmer (do not let it come to a boil) until meat reaches desired doneness (120 degrees on an instant-read thermometer for rare), 15 to 25 minutes. Immediately remove meat from pot, transfer to a plate, and tent with foil to rest 10 minutes.
• If vegetables are not quite tender, continue to simmer them until they are. Taste stock and season with salt and a squeeze of lemon.
• Slice the meat thinly just before serving. To serve, spoon vegetables into shallow bowls and arrange meat on top. Ladle a little of the broth over and around meat and vegetables. Sprinkle with coarse sea salt and chopped chives. Serve with aioli and additional fresh horseradish and beets.