On nice days I often walk from the train station to work, rather than taking a tram or subway. On my way to work I will then walk by the fanciest butcher shop that I know of in Amsterdam (and probably in the whole country): Slagerij De Leeuw. This is not a place to get your daily meat, but for special occasions they have great stuff like organic foie gras, Rubia beef from Spain, and wagyu beef (imported from the US). Wagyu is usually outrageously expensive, but the flank steak (referred to as “bavette”) looked great and almost reasonably priced. The butcher said I should let it come to room temperature, sear it in its own fat (he actually said to also use butter) and let it rest. He said that even though it’s flank steak, it can be eaten like a tender steak since it’s wagyu. I thought I’d also like to try it cooked sous-vide for 24 hours at 56C/133F. And so I decided to try both.
Note added October 10, 2012: a second experiment has shown that 48 hours at 55C/131F is even better.
For the seared version, I seasoned the steaks liberally with salt and freshly ground black pepper. I heated a frying pan to very high heat and put the steaks in with the fat side down. As soon as enough fat had rendered, I seared them quickly on all sides. I was aiming for the rare side of medium rare, so I seared just until nicely browned.
And it also was delicious! It was tender enough and medium rare throughout. I chose to use 24 hours at 56C/133F based on my short rib experiments, taking into account that wagyu is more tender than regular beef. Next time I will try 48 hours at 55C/131F to hopefully get beef that is still slightly more tender and still slightly more on the rare side.