Hi there! For the Warm Shredded Lamb Salad, if I was to use two 2kg bone-in lamb shoulders in the same roasting tin (pushed together), instead of the one 2.5kg joint that the recipe calls for, how should I adjust the cooking time? I would aim to serve the salad at about 6pm.
Nigella's Warm Shredded Lamb salad With Mint And Pomegranate (from NIGELLA BITES gives two options for cooking the lamb. One is to cook the lamb overnight in a low oven (140°C/120°C Fan/gas mark 1/275°F) and the other is to cook for 5 hours in a slightly hotter oven (170°C/150°C Fan/gas mark 3/325°F). If possible, try to have enough space for the hot air to flow right around each shoulder. For the overnight option we would count that as being 12-14 hours of cooking time. If you are using two smaller legs in the same tin then the cooking time will be the same, but it will mean getting up early and putting the lamb in the oven before 6am.
For the shorter cooking time of 5 hours, it will slightly depend on how tightly packed the lamb shoulders are in the tin. If they are very tightly packed into the tin, it may take longer than 5 hours to cook. Lamb shoulder is a very forgiving cut and has a good amount of fat, so is unlikely to dry out with a slightly longer cooking time and it is easier to plan for a longer cooking time than to find the shoulder is not quite ready when you want to serve it. We would suggest allowing 6 hours of cooking time, so the lamb would need to go into the oven at around midday. If the lamb seems to be cooked after 5 hours then you can always remove it from the oven, cover the tin with foil and leave it in a warm, draught-free place until ready to serve.