Season a couple of fat fillet steaks with pepper and put them into two Ziploc bags, squeezing out as much of the air as you can. Then clip the bags onto the edge of the sous vide cooker, ensuring that the steaks are fully submerged. You'll notice that as you place the bags into the pot, the water will displace the remaining air in the bags and force it to the top. Set the timer on your sous vide immersion circulator to 57C for medium-rare (54C for rare, 60C for medium and 64C for medium-well). The length of time you leave it in for depends on how thick your steak is. Here are some guideline times for sous vide steak:
- 1.25cm steak = 15 minutes
- 2.5cm steak = 45 minutes
- 3.8cm steak = 90 minutes
- 5cm steak = 2 hours
As a rule of thumb, you shouldn't leave a steak in a sous vide machine longer than four hours because after that too much of the connective tissue gets broken down and the steak becomes a bit of a mush. 
Set the timer to whatever time's appropriate for your particular steak and then return when the time's up. You'll need to take it out of the bag and 'finish' it. You'll notice that it doesn't look that attractive when it comes straight out of the bag, and a flash fry in a super-hot pan is needed to char the outside. The steak pictured below was finished in a pan with both butter and thyme to add a little extra flavor. The final touch is simply seasoning with salt and pepper. Sous vide steak temp always results in perfection.
Check our comprehensive sous vide steak guide.
