Sous Vide Flank Steak with Arugula Chimichurri

Dining date: 4/9/12

The latest in my experimentation with sous vide has been beef. Actually, the first thing I cooked was beef (a flat iron steak) and I moved over to chicken, pork and lately, I’ve been cooking a lot of fish. Some duck was a gateway back to red meat, and I’ve been playing with a bunch of steaks (short ribs soon to come!).

The thought came to me while I was planning what to bring to an Easter BBQ potluck. I could cook the flank steak sous vide ahead of time and bring the vacuum-sealed bags to the BBQ to be finished on the grill. I think flank steak is a good option marinated and then grilled, but I’ve heard that cooking it sous vide for a long period of time can slowly break down some of the connective tissue to yield a more tender meat. I was sold.

I tried using three different marinade/cooking liquids, each with one pound of steak. The first was an Asian-based marinade with soy sauce, mirin, sesame oil, fresh garlic and fresh ginger. The second was definitely more Western with a reduced red wine (down to almost a syrup), minced carrots, onions, celery, and both fresh thyme and rosemary. Lastly I went with a simple blend of garlic salt and pepper, allowing the meat to bathe in its own natural juices. I sealed up the bags and plopped them into a 131F water bath for 16 hours.

I brought the first two bags (the Asian and Western) to the BBQ, where they were patted dry and finished on an open flame. Given that this was my first time making it, I was a bit nervous – surely I didn’t want to bring a dud to the potluck.

As I sliced into the steak, I breathed a sigh of relief as it yielded perfect end-to-end medium rare meat.  I couldn’t resist eating one of the slices on the spot and was rewarded with pretty good beefy flavor, with each of the different steaks subtly showing off their marinades. It was more tender than usual, having a consistency akin to a slow-cooked beef brisket. I considered it a success and hey, Wolvesmouth approved!

For the last steak, I ended up making it the following day at home. I warmed the bag up in hot water, removed the meat from the bag and patted it try. Lastly I seared both sides with a blowtorch and cut it thinly across the grain, on a bias.

Given that this one didn’t have a marinade, I didn’t want it to be one-dimensional. A sauce to accompany the steak would be ideal, and I had stumbled upon an intriguing recipe a while back. It was an arugula chimichurri, something I thought would fit in perfectly. Garlic, citrus and arugula are all wonderful accompaniments to red meat so I figured together they’d be a sure bet.

Below is the recipe, adapted from Kitchen Daily.

Ingredients:
1 cup arugula leaves, rinsed and dried
1.5 cloves garlic, peeled, or more to taste
1/4 cup extra virgin olive oil, or more as desired
1 tablespoon freshly squeezed lemon juice
salt, to taste 

Directions:
Combine the arugula with a pinch of salt, the garlic, and about half the oil in a food processor or blender. Process, stopping to scrape down the sides of the container if necessary, and adding the rest of the oil gradually. Add the lemon juice, then a little more oil or some water if you prefer a thinner mixture. Yields enough sauce for approx. 1 pound of meat.

The recipe was pretty flexible; it’s really about proportioning the ingredients to personal taste. Balance is key too, since the raw garlic and lemon acidity are both assertive flavors that can easily overpower.

I generously spooned the chimichurri sauce on top of the meat and was ready to dig in. I loved the colors, particularly the vibrant green of the sauce. The flavors were just as vibrant too between the peppery arugula, garlic and bright lemon flavors. It ended up being an excellent accompaniment to the flank steak! I’ll make this chimichurri again since it’s such a good pairing with a nice steak.