on 07/18/19 at 21:51:13:
In that case, with understanding themes presumably more important than cutting-edge theory, I immediately think of Wojo's Weapons, Volume 1. Almost two thirds of it is devoted to the Catalan. It's nine years old now, but given Wojo's technical playing style he likely played lines that were fairly resistant to the winds of theory. And, if MTal likes Lakdawala's writing, maybe the relevant chapter of his How Ulf Beats Black as extra study material.
Off the top of my head I can think of full-length Catalan books targeted to club players by Dunnington, Raetsky/Chetverik (in German), Raetsky/Chetverik (this time in English - an almost entirely different book according to Jacob Aagaard, who was involved in that edition!), Davies and McDonald. I have only the first two of these and picked up some strategic themes just by browsing Dunnington's old Winning with the Catalan, though I don't play either side of the Catalan much.
If we're talking about videos/DVDs, I have no idea what to suggest.
I would second Stigma's recommendation of Wojo's Weapons, Volume 1
, which contains plenty of verbal explanation. Despite the technical character of many of the lines covered in this work, though, theory has moved on significantly almost everywhere. That's the price you pay for playing an opening as popular as the Catalan has been over the past decade.
Again based on what he writes in the other thread, Mtal seems to be interested in the more aggressive lines of the opening, and Nigel Davies addresses those more extensively than a lot of other writers in his book Play The Catalan
. Many of these lines tend not to be covered in repertoire books (which Davies' work is not) and have occurred less in practice over the years, so this might be a good place to find ideas that have proved 'resistant to the winds of theory', as Stigma so eloquently puts it.
I don't have McDonald's book, but he is generally a diligent writer who explains ideas very clearly, so, I'd certainly investigate this if I was taking my first steps in learning to play this opening.