Sous Vide Beef Tenderloin with Bone Marrow Emulsion and Crispy Prosciutto

Season the beef tenderloin generously with half of the Maldon sea salt. Place in a vacuum pouch with the beef tallow and seal at high vacuum. Submerge in a water bath preheated to 54 degrees Celsius for 2 hours.

Roast the canoe-cut marrow bones at 200 degrees Celsius for 15 minutes until the marrow is rendered and soft. Scoop out the warm marrow and strain through a fine mesh sieve. In a high-speed immersion blender cup, combine the egg yolk and lemon juice. Slowly drizzle in 60 grams of the warm, liquid bone marrow while blending continuously to form a thick, glossy, warm emulsion. Season with a pinch of salt and keep warm in a water bath at 50 degrees Celsius.

Lay the prosciutto slices flat between two sheets of parchment paper sandwich-pressed between two baking sheets. Bake at 180 degrees Celsius for 12 minutes until completely dehydrated and crisp. Cool and shatter into delicate shards.

Remove the beef tenderloin from the vacuum bag and pat extremely dry with paper towels. Sear in an smoking-hot dry cast-iron skillet for 30 seconds per side to develop a micro-thin Maillard crust. Slice the beef into thick medallions. Spoon a swoosh of the warm bone marrow emulsion across each plate, arrange the beef medallions on top, scatter with crispy prosciutto shards, and finish with a sprinkle of Maldon sea salt.