To clear up any confusion regarding how to get this achievement,
you can get it on your first normal play-through.
This requires you to complete
two optional missions that become available during different parts of the story, and are found in two different locations on Elpis.
The first part of this achievement is done by completing a quest called
"The Voyage of Captain Chef". This mission is avaliable after completing story mission "Let's Build A Robot Army" and you unlock
Once you've progressed to this point in the game, you can head out to
Triton Flats and look for Captain Chef on your echo map labeled "!". He is an older gentleman that is standing next to a spacecraft. Talk to him to accept the mission, and complete the tasks he asks you to do. (Most of it involves him saluting his flag and you defending him or hoisting the flag up further.) Once you finish this mission, you can relax and set this on the back-burner because the next part of it doesn't become available until later in the story.
The second quest needed for this achievement is called
"The Return of Captain Chef". It unlocks after completing story mission "Eye to Eye" and unlocking
After exiting Helios and returning to Elpis, you will find yourself in a vast land called
Vorago Solitude. Once again, you can find Captain Chef labeled "!" on the southwest part of your map. Meet him and he will have you do the same tasks once more. (Hence the name of the achievement, right?)
The achievement will pop after you complete both of the missions aforementioned.