Add the diced celeriac to the cream in a pan and simmer until tender (approx. 25 minutes). Then blitz to make into a purée.
Sous vide steak for 45 minutes on 55 degrees (for medium rare). Or, pan fry the steaks to medium rare.
Peel and cut the potatoes into cubes and pan fry in butter, 1 clove of garlic and rosemary, in an oven-proof pan, until golden on one side. Turn over the potatoes and cook for a further 5-6 minutes, or until golden-brown on both sides. Add the chicken stock to the pan and then simmer for around 10-15 minutes or until the potatoes are soft.
Peel the shallots and cut into rings and place in milk for around 10 minutes to soften.
To make the jus, reduce the port in a pan and add the beef stock, reduce further and add a knob of butter to give a glossy finish.
If you have sous vide the steaks, you need to remove when cooked and pan fry both sides to get a coloured and crisp finish.
Saute the mushrooms in garlic butter.
Place the shallot rings in cornflour, then fry lightly in hot oil.
Pan-char the shallot quarters until black.
Put a few drops of celeriac purée on each
plate and smear in different directions.
Cut each piece of steak in half down the middle and lay one half in the middle of each plate. Then, lay the other slice just off centre.
Dot the potatoes around the plates and put the shallots and mushrooms in place on top of each steak.
Finally, top with crispy onion rings.