Season the lamb with salt and pepper and let sit in the fridge, uncovered, overnight.
Heat a sous vide water bath to 131F degrees.
Place the lamb in a vacuum seal bag with the garlic and seal.
Cook in the water bath for 6 hours.
Remove the lamb from the bag and pat dry (reserve garlic cloves if desired).
Heat a cast iron skillet or grill over high heat.
Sear the lamb on all sides until golden brown.
Slice and serve with mint chimichurri and reserved garlic if desired.
Mint Chimichurri:
Combine all ingredients, except the olive oil, in a food processor and pulse until everything is chopped. You want it to be slightly chunky, so it doesn't need to be totally blended.
Stir into the olive oil and serve with the lamb chops.
Notes
Make sure the leg of lamb you buy fits the size of your sealable bag and water bath. If it’s too big, you’ll need to cut it down to fit.
For the best results, buy a leg of lamb with the shank removed. It will be easier to fit in the water bath and to carve.
If you only have a butterflied leg of lamb, you’ll want to truss it (roll and tie it) before cooking it in the water bath.
For the best sear, pat the leg of lamb dry with paper towels when it comes out of the water bath.
Make sure your cast iron skillet is hot before browning the lamb. This will ensure the lamb sears quickly without over cooking.
Instead of searing, you can broil the leg of lamb in the oven to achieve the browned crust.
Don’t throw out the garlic cloves. Save them to serve with the lamb.
When sealing the lamb in the bag, make sure air is removed from the bag so bacteria doesn’t get in.
For even cooking, the bag of lamb should be fully submerged in the water bath. To help prevent floating, you can weigh the bag down with something heavy like a sous vide sinker weight.
When making the chimichurri, use fresh herbs and don’t over process the herbs as you want the chimichurri to be a little bit chunky.