I've recently purchased a sous vide immersion circulator in preparation for Christmas. In my home we typically cook lamb on Christmas (don't ask..). The way that I usually cook a shoulder of lamb is by searing it in a skillet so that it is well-browned all over and I then place the shoulder in a very hot pre-heated oven. I then cover the tray in foil and immediately turn the temperature to 80 degrees celsius and then I let that cook for 7 hours or so. The resulting shoulder is fall off the bone tender, moist and unctuous because the collagen and fat have been rendered. I'd like to recreate the same thing using the sous vide method.
My family are very queasy at the thought of meat being even the slightest bit pink so ideally I'd like to avoid this. My biggest concern besides this is that the meat will become mushy if I cook it long enough for the collagen and fat to become tender and that it will look "boiled" as opposed to "roasted".
So my question is:
How can I achieve this same result with the sous vide immersion circulator?
What temperature would I have to sous vide the lamb at and for how long?
Also would it be advisable to sear it beforehand and then sous vide it? or sous vide it and then finish (to give it a brown roasted exterior) it off in the oven?
I would sear first, both to begin flavor development and to kill any bacteria on the surface of the meat. Bag with or without herbs and a small amount of liquid. Cook sous vide for 18 - 36 hours at 165F/74C for well-done/traditional braise texture. Then before serving, I would have a very hot oven ready. Carefully remove from bag (it will be very tender), pat dry, and finish in hot oven to finish browning.
At the end of the day, you just may prefer roasted/braised to sous vide. It's just another tool/technique.