Add <quantity>4</quantity> egg yolks to a tall jug

Add <quantity>1<unit>tbsp</unit></quantity> of miso and <quantity>2<unit>tbsp</unit></quantity> of white wine vinegar

Add <quantity>3<unit>tbsp</unit></quantity> of soy sauce. Mix with a hand blender until homogeneous

Add <quantity>2/3<unit>cup</unit></quantity> of sunflower oil in a thin stream while beating until emulsified. The Miso Mayo is ready

Cut <quantity>½<unit>cm</unit></quantity> thick slices out of <quantity>200<unit>g</unit></quantity> of hanger steak

Transfer the slices to a tray greased with extra virgin olive oil and place it in the freezer for 10-15m to firm

Thinly slice the green part from <quantity>½<unit>bunch</unit></quantity> of scallion. Transfer it to a bowl with iced water. Keep the white part

Thinly slice the white part from the scallion and reserve

Thinly slice <quantity>2</quantity> white button mushrooms

Remove the sliced meat from the freezer and small dice it

Season the diced meat with extra virgin olive oil to taste

Add ground black pepper and salt to taste

Add the white part of the scallion to taste and mix it

Divide the meat into <quantity>2</quantity> plates and add the green the part of the scallion on top

Add the Miso Mayo and white button mushroom slices to taste. The steak tartare with miso mayo & mushrooms is ready

Enjoy!