* To make the cooked yolk: egg yolk(67grams), lemon juice (1.3 grams), salt (0.33 grams).
Mix all the ingredients in a bowl. Seal completely in a cook-proof vacuum bag and cook in a steam oven for 30 minutes at 60 degrees. Cool quickly in ice water and work the mix by hand to avoid excessive clotting. Set to one side.

* For the vinaigrette: sunflower oil (18 grams), Dijon mustard (15 grams), water(12 grams), ketchup(4 grams), whisky (4 grams), Perrins Worcestershire Sauce(3.5 grams), fine salt(1.5 grams).
Mix the mustard, the water, the ketchup the whisky, the Worcestershire Sauce and the tabasco. Add salt and pepper and make an emulsion with these ingredients using the oil. Set to one side.

* Set-up and presentation: gherkins (15 grams), capers (15 grams), fine salt(4 grams), spring onion(12 grams), sliced bread(4 slices), steak tartar vinaigrette(60 grams), cooked yolk(60 grams), matured ox meat (500 grams), ox fat (15 grams), common chickweed (8 grams).

On a very hot grill, toast the bread until it is golden on both sides, using the ox fat, mince the ox meat and baste with the vinaigrette, checking the salt level. Finely dice the gherkins, the capers and the spring onion. Cut the bread in half without reaching the end, in such a way that it can be filled with ease. Incorporate the cooked yolk to the base of the bread, then covering it with fried onion.

Complete the roll by filling it with the steak tartar, carefully so that the bread doesn’t break. Decorate with 5 dots of yolk and some chickweed shoots.

Recipe for 4 people.