Cook the rib section sous vide

• Place the rib section in a vacuum bag with the herb sprigs and seal.
• Cook sous vide for 1.5 hours at 57 °C.

Make the tangzhong

• Mix the water and flour in a small saucepan.
• Cook over medium heat, stirring constantly, until thickened into a sticky paste.
• Remove from the heat and let cool.

Prepare the egg wash

• Whisk the egg with a little water and a pinch of flake salt until smooth.
• Cover and refrigerate until needed.

Activate the yeast

• In a bowl, whisk the dry yeast, water and skimmed milk powder until fully dissolved.
• Let it sit for 5 minutes.

Mix the dry ingredients

• In a large bowl, combine the flour, potato starch, salt and sugar until homogeneous.

Knead the brioche dough

• Add the yeast mixture, butter, tangzhong and eggs to the dry ingredients.
• Mix until a uniform dough forms, then knead until it passes the windowpane test, about 10-12 minutes on high speed with a mixer.

First rise

• Cover the dough with a towel or plastic wrap.
• Let it rise until doubled in size.

Shape the buns

• Deflate the dough and divide it into desired portions.
• Fold the edges inward, turn each portion over and form tight balls with a smooth surface.
• Place on a baking tray lined with parchment paper.

Second rise

• Let the buns rest until doubled in size again.

Bake the buns

• Preheat the oven to 165 °C.
• Brush the buns with the egg wash.
• Bake until cooked through and golden.

Make the pear vanilla jam

• Puree the pears into a smooth paste and weigh the total amount.
• Add the pear puree, an equal weight of jam sugar, the vanilla bean and seeds and the thyme to a saucepan.
• Cook according to the jam sugar package instructions, about 4 minutes at a boil.

Finish the jam

• Add the butter, a little white wine vinegar and a pinch of flake salt.
• Let cool completely, then whip again until smooth and light.
• Transfer to a jar and refrigerate until needed.

Make the truffle mayonnaise

• Whisk together the egg yolks, Dijon mustard, lemon juice and sugar.
• Gradually add the oil while whisking continuously to emulsify; a blender can also be used.
• Season with white wine vinegar, flake salt and the finely grated truffle.

Sear and slice the steak

• Heat olive oil in a large frying pan and sear the sous vide steak on both sides.
• Let it rest, then slice to the desired thickness and season with black pepper and salt.

Assemble the sandwiches

• Slice the brioche buns.
• Spread with truffle mayonnaise and pear vanilla jam.
• Fill with arugula, sliced steak, Parmesan and sliced truffle.