[![a picture of the mystery cookware][2]][1]

I asked a question about a "[Wonder Pot][3]" a bit ago, and this item came up on a search. I don't think it's a wonder pot though. The center hole is effectively much smaller, and there are not any vents in the lid. There isn't a "flame tamer" either, although this part may be lost. 

I keep seeing cookware like this in thrift stores, and I'm pretty sure it's for one specific task. What might that task be?


  [1]: http://www.ebay.com/itm/Unique-Steamer-Wonder-pot-Inverted-Center-9-Stovetop-Pan-w-Lid-Cookware-/190594578412?pt=Cookware&hash=item2c605277ec
  [2]: https://i.sstatic.net/FH3An.jpg
  [3]: http://cooking.stackexchange.com/questions/15137/where-can-i-purchase-a-wonder-pot