Chef Magnus Nilsson was a guest on UK TV’s Saturday Kitchen last weekend. His hilarious performance in the ‘omelette challenge’, where chef guests compete to make an omelette at record-breaking speed, nicely summed up for me everything that is wonderful about his approach to food and cooking. While Nick Nairn had already finished throwing together a scrambled-looking object at breakneck speed (around 17 seconds), Nilsson had barely got his eggs cracked, and only had a half-melted lump of butter in his pan. He swore mildly at his too-hot pan, and allowed the show’s host to press him into making the ‘omelette’ anyway – but it was clear that for him, this wasn’t an omelette. Without the requisite care, it wasn’t even really food. For him, the whole thing quite clearly did not compute.

I’ve been noticing this business of time on every occasion I try a recipe from Nilsson’s Fäviken cookbook. In addition to his unobtainable local ingredients (he brought a beautiful piece of Swedish moss to the UK to make his own dish on TV), he uses all sorts of elements that simply take a long time to prepare in themselves. One obvious example is the cured egg yolks I’ve been working on for nearly three weeks now – an incidental but vital item in a lichen recipe. For today’s beef and onion recipe, I needed 12 hours to collect enough whey for the sour onions (easy), and I needed to forget about the idea of ageing my beef for 20 months (not so easy). I also needed to adapt to a very slow but magnificent new way of frying a steak. I’m learning that in the world of Fäviken there is no such thing as rustling up a quick snack from a few things in the store cupboard – unless of course you’ve been working hard on that cupboard’s contents for a year or two.

With all this in mind I decided to try the “Ribeye of beef dry aged for twenty weeks, sour onions, turnip thinnings and green juice” (p. 76), an ostensibly straightforward dish made more complex by technique and a few special ingredients. I must confess to several compromises. My beef was not aged for 20 months, and I had a thin steak not a thick one. I had no turnip leaves or lovage so I forgot about the first and substituted the latter with a mixture of celery leaves and fennel fronds. My whey, from sheep’s milk yoghurt, was not ‘crystal-clear’ as requested, but yellowish.  I had no birch leaf oil, and all I had fresh enough to substitute for it was walnut oil, not at all the same thing. I think you get the idea that my version is approximate. If you can get any closer to the original, I salute you. But don’t worry if you can’t. Even the compromised version I managed was utterly delicious. The technique for cooking the steak built up a delicious crust around a rare centre, and juiced leaves and sour onions could just become my new side-dishes of the season.

Ribeye steak with sour onions and green juice (for two people), adapted from Magnus Nilsson’s recipe

Ingredients
2-3 large handfuls of celery leaves and a few fennel fronds
500g beef ribeye steak
100g mild garlic butter
100-200g butter
150ml whey drained from cow or sheep’s milk yoghurt
1 medium onion, sliced paper thin
1 dessert spoon double cream
1 tsp walnut oil
coarse salt

Method
In the morning, pour your yoghurt into a sieve lined with muslin over a bowl, and place in the fridge. It is difficult to be precise about how much yoghurt to start with, as it all depends on how thick it is already. Mine was very thick and I drained 500g for 12 hours to obtain 150ml of whey, but would expect to yield about twice as much from runny yoghurt.

Wash the leaves and set aside at room temperature. Save 6 for serving and have the rest ready in a juicer.

Make sure the meat is out of the fridge to dry and warm up to room temperature at least 2 hours before you are cooking it. Salt it (fairly generously) just before you are ready to cook it. If you let the salt dissolve a bit this will help the meat brown more evenly.

Brown a large spoonful of butter in a frying pan and fry the meat on each side in turn, keeping it moving in the pan, until it is caramelised on both sides.   Let the meat rest somewhere warm but not hot, brush it with a little of the garlic butter, and leave it to stand until it is no longer hot to the touch. Strain the fatty buttery juices off the resting meat (not from the pan) and set aside. Clean the pan and repeat the process, doing this as many times as you need to until the meat is cooked to your liking (I only did it three times for my thin piece of meat).

While the meat is cooking, reduce the whey in another pan until you have 1/10 of the original quantity left.

Add the onions and a little plain butter to the pan and cook them for 5-10 minutes, turning them very gently with a heatproof rubber spatula so as not to break them up. Do not allow them to brown.

When they are cooked, finish with the cream. Do not add any salt, and do not make them ahead of time as they won’t taste the same if not served immediately.

Finish the meat. Return the you fat strained from the resting meat earlier to the clean pan, and fry the meat in this until it is hot. You can add a little more butter and let it brown before removing the meat from the pan, if you like. Cut into strips and divide amongst two plates.

In the last few seconds push the leaves through a juicer into a vessel that already has the oil in it – this preserves the bright green colour. Add to the plates along with the leaves you saved earlier, and serve.