There appear to be pages missing from the node red cookbook index. For example the join streams page is not there. Unless I am going blind.
If you think there is an problem, you're welcome to raise an issue or a PR to fix anything - https://github.com/node-red/cookbook.nodered.org
In this instance, the recipe you mention is in the index - called Create a single message from separate streams of messages
Doh, I said unless I am going blind. Though I think in this case it was more to do with brain fade, with the one I was looking for being down the bottom of the Flow Control group after several Trigger flows etc. Sorry for the noise.