Quickly sear the meat on both sides, either in a pan or with a blowtorch.

Season with salt and pepper and vacuum-seal the meat.

Cook it sous vide/water bath for 60 hours at 62 degrees Celsius (144 degrees Fahrenheit).

Take the meat out of the bag and pat it dry. Save the liquid from the bag for the gravy.

Heat a pan to high heat and add oil when hot. Place the meat in the pan with butter and give it 30-45 seconds on each side.

Sprinkle the meat with salt and pepper and it's ready to serve.

Peel the potatoes and boil them in salted water for about 20 minutes. If you stick a sharp knife into the potatoes, they should fall off when you lift the knife.

Start by washing the celeriac and "peeling" it. Cut it into small squares of max 2 x 2 cm. Sprinkle salt over them and let them sit for 30 minutes.

Bring the vinegar and sugar to a boil in a heavy-bottomed pot and add a bit of horseradish and apple cubes.

Pour it over the celeriac squares in a glass jar with a lid and place it in the refrigerator. The longer it sits, the better. However, give it at least 5 hours before eating.

Prepare the ingredients by removing the outer leaf from the leek and pointed cabbage and trimming the ends of the celery. Cut them into approximately 1.5-2 cm chunks and fry them over medium heat for 10-15 minutes in a pan with butter. Season with salt and pepper at the end.

Start by making a roux.

Melt 10 grams of butter over medium-high heat and add the 2 tablespoons of flour. Whisk quickly and add the milk. When it thickens again, add the stock, and then the cream.

Season with lemon juice, sugar, salt, and pepper. When you take the meat out of the sous vide and dry it, use the meat juices from the vacuum bag in the gravy.

If you are not satisfied with the color of the gravy, you can always use browning.