You’ll get taken to a random community. Once you arrive there’s a link at the top of the page to /r/random so you can just hammer away at that until you get somewhere that’s the right combo of random and interesting.
There is also /r/randnsfw that takes you to a random nsfw communty if your instance has them.
Thanks. It seems to land on the same few comms for me. Do you get a new comm every time?
Well for me it does not even work today. I get no result.