Make sure to preheat the oven to 180 degrees Celsius (356 degrees Fahrenheit).

Find a heavy-bottomed pan and make sure it gets really hot.

Add the oil and place the two steaks on the pan.

After about 2 minutes, add the butter and rosemary sprigs, and continue cooking for another minute before flipping the steak and giving it 2 minutes on the other side.

Place the steaks in an ovenproof dish and put them in the oven to finish cooking for about 8 minutes at 180 degrees Celsius (356 degrees Fahrenheit) in a conventional oven.

Let them rest (not under aluminum foil) for a couple of minutes before serving.

Halve the pointed cabbage, rinse it, and remove the outer leaves.

Sauté it over high heat in the butter/oil/rosemary mixture left in the pan from cooking the steaks.

Once a sear has formed, reduce the heat and sauté for about 10 minutes, then add the lemon juice.

Let it simmer for a few more minutes, and the cabbage is ready to serve.

Peel the potatoes and celery root, and cut them into cubes.

Melt the butter so it's ready when the root vegetables are tender.

Boil them in unsalted water for about 15 minutes until they are tender.

Drain the root vegetables and mash them coarsely while adding whole milk and the melted butter to reach the desired consistency.

Season with salt, pepper, and lemon juice to taste.

Peel the Jerusalem artichokes and pat them dry thoroughly.

Slice them very thinly using a mandoline slicer.

Pat them dry again with a tea towel.

Heat the oil in a pot to about 180 degrees Celsius (356 degrees Fahrenheit).

Fry the slices in small batches until golden.

Ensure you don't add too many slices at once, as the oil temperature will drop when they are added.

Briefly pat them with a tea towel or paper towels and sprinkle with good salt.