The easiest time to do this is after you have done a few of the side missions, killed a couple of small monsters, and have carved them for some raw meat.
After you unlock the first camp, Ancient Forest, go to Depart on Expedition, select either Southwest or Northeast camp and depart. Once you arrive, press and hold LB, use
and select "BBQ Spit" (bottom right).
Your character will sit down to roast and a song will play. Count out 4-5 seconds, press
, and you should have a well done steak and the achievement. If the meat has turned black, it has burned and will not count.MrNoLuckFox
pointed out the song in the background helps, but it is possible to wait too long if not paying attention. Using the song as guidance and counting out 4 seconds should be enough to earn you the achievement.