Hi Merrybaker,
It may be the case that the oil could be used to make a curry after being used to cook popadums but AND THIS IS FACT, if the oil is used to cook curry AND THEN used to cook Popadums THE POPADUMS WILL TAKE ALMOST ALL OF THE COLOUR FROM THE OIL. In my neck of the woods popadums are always very very pale almost white, so curry and then popadums does not work.
hope this helps,
Blondie