Aged beef, mushroom, beef fat

For the beef:
Blend the egg yolks and vinegar in the Thermomix, at 63°C, until it becomes a sabayon. Ensure the beef fat is just above room temperature. Slowly add the fat to make a thick mayonnaise consistency, while letting it down with the soy sauce. Transfer it into a squeezy bottle, for serving.

For the tatare dressing:
Mix all of the ingredients together and then mix together with the diced beef.

For the dressing:
Mix all of the ingredients together and then mix together with the tartare dressing.

For the pastry tubes:
Roll around an already lined thin tube. Deep fry, at 170°C, for 6 minutes, until crispy. Remove from the fat and leave to cool for 5 minutes, then remove from the tube.

For the brioche discs:
Cut out discs with the tube you are rolling the feuille de brick around. Cook the discs in the oven to dry out and crisp up.

For serving:
Place a brioche disc in the bottom of the tube. Fill with the beef tartare. Top with cornflowers.