If you want something along the lines of traditional results you can cook it between 150°F to 176°F (65°C to 80°C) for up to a day. For a tender steak texture I prefer lamb Osso Buco when cooked for 1 to 2 days at 131°F (55°C). If you prefer your lamb cooked medium, 140°F (60°C) for the same length of time may hit your sweet spot.