Fastest (legit) way is to log out and change your config to re-enable the mass-fabricator ( which is a legit part of IC2 removed by gregtech. ) You can change this in the gregtech config.
Other than that, you get a whole lot of massive quarries and go to bedrock. Keep a close eye on them, and manually dig up the iridium ores with a rockcutter or other silk touch pick so you can macerate it and get 2 ores.
However, by default you will find approx. 1 Iridium ore for every 5 chunks. That's a 16x16 area...and they can spawn at ANY height, so you need to dig it all up. Yea...even with silk touch and 4 quarries you are looking at days.
Don't think it'd get much easier at that point though. It'll cost you 100 million EU and giant mounds of scrap to get 1 UU Matter, and you need 7 of those per Iridium.
Mass Fab is 1 million EU to 1 UU matter, and does not require scrap. Instead, if it is fed scrap it only requires 166,666 EU per UUM.
Considering how much Iridium you need, if you don't want to spend weeks working with a dozen people, you need to re-enable the standard Mass Fab.