Behind Enemy Lines
If you're still welcome in Outcast HQ (ie you agreed to let Sloane execute Vehn), you can pick up this quest up from Kaetus as part of the overarching Settling Kadara questline).
Speak with the Turian Outcast to learn that a few Kett may have survived Sloane's purge from her initial takeover. It's just rumors, but he gives you a navpoint to investigate. Drive out to find a crashed shuttle (brought down by Kett weaponsfire) and a lone Angaran survivor.
Talk with him, then follow your radar to some footprints, by another dead crewman.
Keep following the trail. The prints are far enough apart that it's worth taking the NOMAD. Resist the urge to skip ahead, because it sometimes messes with the quest triggers.
The trail will eventually lead to a big, suspicious cave.
Enter and pop the door to trigger a cutscene where Sloane and Kaetus join you.
As you bicker, The kett attack. They're pretty dug-in here, but there's not quite so many as you might expect, given the size of the place. There are Destined and Anointed, but no Ascendant or Fiends. So no heroic measures called for, though keep an eye your ammo- it's easy to run dry in this target-rich environment.
When the last one falls, you get a heftyish Viability bonus, and technical mission completion.
Tie things up by looting the caverns, and having one last convo with Sloane as you exit.