How do you like your leg of lamb?
There is debate as to the exact definition of “rare,” “medium rare,” “au point,” etc. A little practice will help you learn just exactly what temperature achieves your preferred appearance of doneness.
Here are some basic temperature setting guidelines:
Rare: 129 F/54 C.
Medium: 135 F/57 C
Medium to Medium well: 140 F/60 C.
Well done: 150 F/74 C.
When guests in restaurants and hotels specify their preference for appearance of doneness, the chef will add heat to individual orders, hopefully achieving the desired level of doneness. This is usually done by dipping the individual cut in stock or broth, aka “jus.” Exposure to hot liquids can cause the meat to “clinch,” so the jus should NEVER be hotter than 165 F/74 C.
Level of difficulty: 2.5
Preheat the water in your sous vide bath to the temperature that most closely matches your preference. For this demonstration, we used 130 F/54 C.
Let sous vide timing work for you!
Among sous vide’s several unique characteristics, cooking time is determined by the shortest distance from the surface of the roast to the geometric center instead of by weight. Many newcomers are daunted at first by what appears to be an inconveniently long period of time required to sous vide process proteins.
The fact is, the rate of collagen conversion in this range of temperatures is very gradual. This means that the texture and appearance of a roast processed for 8 hours will differ only slightly, if at all, from a roast that has been processed for 16 hours. Some people want to start their roast in the early morning to serve for dinner that evening, so the 8+ hour interval is convenient for them. Others would rather start it the evening before and sleep in! Both approaches are favorable!
Processing the roast
After vacuum sealing the leg of lamb, process at the appropriate temperature for
8-16 hours, as per your convenience and regardless of the weight.
After processing, shock the sealed pouch in iced tap water to 70 F/21 C before refrigerating. This is a very important safety procedure. The air in refrigerators/freezers is not capable of cooling the pouch fast enough to meet food safety guidelines. After shocking, refrigerate at 40 F/4 C until you are ready to move on to the next step.
Submerge the sealed pouch for 5-10 minutes in a preheated sous vide bath or hot tap water (110+ F/44+ C). This will fully melt the gel. Cut open the bag, drain the juices and set aside. Click HERE to learn how to clarify the juices for use in any recipe that calls for stock or water.
Preheat the oven to 350 F/176 C.
Place the roast on a sheet pan for roasting. I use a sheet of parchment for quick and easy disposal afterwards.
Dust the top side of the roast with flour (optional).
Coat the roast with the egg white mixture to create a sticky surface.
Sprinkle liberally with the seasoning mixture.
Turn the roast over.
Dust again with flour…
and apply the egg white mixture again.
Repeat the seasoning process.
Stage the roast into the preheated 350 F/176 C oven.
Roast until the surface achieves the desirable appearance and the internal temperature is at least 125 F/52 C–approximately 1.5 hours.