What is this crock with 2 lids and a strainer?

[books6050]

I picked up this little crock (7" talll x 8" diameter) at a garage sale thinking it was for making sauerkraut but quickly realized that’s not what it’s for.  It has an outer lid, an inner lid, and a strainer lid that sits  about 2” off the bottom.  It appears to be contemporary and unused with no markings.  What the heck is this thing for? 

[a*river*runs*through*it]

@books6050

It looks like an insert for a Crock Pot with a steamer insert.

[books6050]

Thank you for that suggestion.  It's the best one I've had so far.  Unfortunately I have a small and an oval crock pot so I can't try it.  Maybe the neighbor's...