How to cook roast potatoes at low temperatures? Is there a sane way of roasting potatoes at low temperatures?

I ask because I am pot roasting a silver-side joint and would like some roast spuds to go with it. However, the pot roast is to be done at 140c and the spuds need roasting at around 200c. 60 degrees is a big difference, if it was 10, maybe 20 I'd just throw them in regardless.

If the potatoes roasted in say 20 minutes, I'd just roast them as the joint rests, which is how I do my Yorkshire puddings. Sadly, the potatoes end up taking to an hour or so, and I really don't like reheating just rested joints of meat.

How can I go about doing this?
Yes. What you can do is throw the potatoes in with the meat - anything above 85C will eventually cook the potatoes through. Then when you pull the meat out to rest, raise the oven temperature to say 190 - 200 C and possibly add a little fat. They won't take long to finish roasting to a nice golden brown.