If you have 3 good regen atma (Mounted Champion, Vicissitude, and Stronghold), put them on and go solo mandies in Tahrongi or whatever other zone of your choice. You probably won't even need Phalanx, so just keep yourself hasted, wear haste gear, and eat a cheap ACC food like crab sushi. I can't promise it'll be super swift, but having a Joyeuse or other multi-hit weapon will help. On the other hand, if getting TEs is of no real concern, you could also grab a weaker sword and pretty much just AFK whack things for the 9 minutes of Haste you'd have with Composure up.