I asked a question about a "Wonder Pot" 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?