Two joints of lamb, one oven - timing....

[ReallyTallTony]

Hello,

For Christmas I have learned I am cooking for an additional 14 (!) people for dinner, we are having lamb as the main roast.

My oven is not big enough to take a large joint of lamb in one piece but could take two smaller joints, one above the other.

My question is, aside from rotating periodically to make sure the cooking is relatively even, is the timing for (example) a single 4KG joint of lamb, the same as two 2kg joints? As once the oven gets back to temperature after the meat is put in, I think the cooking time is the same for any number of 2kg joints put in.

Does this make sense, and can anyone advise?

Many thanks,
Tony (maker of some mean roast potatoes)

 

[buckytom]

Welcome, Tony.

Yes, you have to cook them per weight as if they were the only one in the oven, or you'll overcook them.

Be sure to use a meat thermometer for accuracy.

Hmm, how 'bout sharing a spud recipe or two for a Plastic Paddy (Irish-American guy).

 

[jennyema]

Cook them to temp with a thermometer and not to time

 

[CWS4322]

Welcome, Tony! When working in a restaurant, we would rotate top to bottom and turn the pans. Use a thermometer and set a timer to remind you to rotate and turn the pans.

 

[dragnlaw]

Welcome to DC Tony!

You might find that you'll have to add an extra 15 min. or so, to the total cooking time. This would be due to opening oven to rotate, etc, and loosing heat.
That having been said: you still take it out about 5 to 10 degrees below what you are aiming for. It will finish while resting. For medium rare it is 145 degrees, approx. 25/30 min. per lb/500 g.

Sounds like this isn't your first experience in the kitchen, but just thought it worth mentioning.