Sous Vide Leg of Lamb With Black Olives Recipe

The other week, I found myself swamped with boneless lamb legs while testing various temperatures and timings for my sous vide lamb with mint, cumin, and mustard seed. When I finally nailed the recipe, I still had a few left, so I figured, why not use them for another recipe?

I immediately thought of pairing the lamb with black olives. Musky lamb with salty black olives is a flavor combination I've loved ever since my old chef Barbara Lynch put an olive-crusted lamb on the café menu at No. 9 Park. We'd rub the outside of the lamb with an olive paste before pan-searing it and serving it with a blue cheese fondue for dipping (it was the kind of dish designed to make you want to drink). Instead of putting those olives on the outside, here I decided to put them on the inside.

I started out by combining pitted Kalamata olives, parsley, and garlic in a food processor and blending them together with some extra-virgin olive oil. The mixture is very similar to tapenade, though it lacks capers, anchovies, and the overt garlic punch you'd find in a more traditional tapenade. (I actually tried a version with anchovies and found that, at least when they're cooked sous vide, their flavor can become a little overpowering.) I then rubbed it all over the interior of a butterflied lamb leg, applying it in a thick layer. I also made sure to save a little of the mixture to use as a sauce when serving (and, okay, to spread on some crackers with blue cheese while I waited).

Next, I tied up the lamb using butcher's twine to help it keep its shape while cooking, and to make sure the olives stayed locked inside. The trick to tying up an unwieldy piece of meat like this is to start from the ends and work toward the center, alternating sides. This prevents the filling from squeezing out of one side, like a tube of olive-flavored toothpaste. Because olives are so salty, there's no real need to add extra salt to the interior of the lamb, but it's still important to season the exterior with salt and pepper.

I preheated my sous vide water bath, placed the lamb in a large zipper-lock bag, then lowered it into the bath, using the water displacement method to remove the air from the bag.

Lamb legs are quite large, so they take at least a couple of hours to cook all the way through to the center. The nice part about cooking sous vide, though, is that after those two hours are up, you still have a pretty large window of time during which the lamb will remain perfectly cooked. Anywhere between two and six hours, and you're good.* This is good news for those days when you plan dinner for 7 p.m., but 6:45 rolls around and you're stuck in the middle of that All in the Family marathon. Go ahead and eat late; your lamb will be waiting for you.

*The only exception is when you're aiming for lamb cooked below 130°F (54°C). At those temperatures, bacteria can flourish, so it's not recommended to cook the lamb any longer than three hours for food safety reasons.

When you finally are ready to eat, it's as simple as taking the lamb out of the water bath, patting it dry with paper towels (water is the enemy of good browning), and searing it to add color and flavor.

I seared my lamb in oil in a ripping-hot cast iron skillet. Cast iron is nice and heavy, which allows it to retain a ton of energy, so it can put a nice sear on the lamb in a matter of minutes. (When cooking sous vide, it's important to try to sear your meat as rapidly as possible to avoid overcooking the flesh just under the surface.)

Because foods cooked sous vide don't have a significant temperature gradient inside, they're ready to slice and serve immediately after cooking—no need to let them rest. I cooked my lamb at 128°F (53°C), which gives it a deep rosy-red hue from edge to edge, with a tender bite that offers just a slight meaty chew and plenty of lamb flavor to work with the black olives.

In other words, it's just about perfect. Though I suppose a little blue cheese fondue on the side couldn't hurt.