Roasting sirloin which has already been cut into slices I was intending to cook roast beef with a joint of sirloin, but unfortunately my wife has returned from the supermarket with the sirloin already cut into slices (it wasn't her fault, and I don't know why the butcher sliced the meat). My question is: would it still be possible to roast the sirloin as if it were one joint or should I try a different cooking method?
You could try tying it up into the original shape, but the trouble is that you've got cut surfaces which have been exposed to bacteria, and which will not reach a high enough temperature to kill them  unless you're going to cook it to death, so I wouldn't recommend this. It seems you've actually got sirloin steaks, so why not just cook them as such?