Prepare the sous vide circulator. Fill a large bucket or pot with water, then attach your sous vide circulator and set desired temperature for lamb. For medium-rare lamb, internal temperature should be between 125F and 134F. For medium, the internal temperature should be between 135F and 144F. I set mine to 132F.
Season the lamb chops. Sprinkle lamb evenly on both sides with 1 ½ tsp Kosher salt and ¼ tsp black pepper.
Prepare the lamb. Place seasoned lamb chops in a vacuum seal bag, then add 3 thinly sliced garlic cloves, 2 sprigs oregano, and the peel of 1 lemon. Use the vacuum sealer to remove air from bag.
Cook the lamb chops. Place sealed bag with lamb chops in the preheated pot of water, then set a timer for 3 hours (or up to 4 hours). Remove bag from water, cut open, and dry lamb on a paper towel-lined plate.
Reverse sear the lamb. Heat a large cast-iron skillet over high heat. When very hot, add 2 Tbsp extra virgin olive oil and 2 Tbsp unsalted butter. Add 2 smashed garlic cloves and remaining sprig of fresh oregano. Carefully add lamb chops, then sear for 45-60 seconds per side, flipping once. Allow lamb to rest for 5 minutes before serving with a pinch of flaky sea salt on top.
Note: USDA recommends an internal temperature of 145F with a 3 minute rest