Sometime after visiting Kadara, pass by Kesh's office in the Nexus to notice a Wilma, lurking outside and hissing at you. Talk to her for a quest to find some special liquor on Kadara.
Your navpoint will take you to the market, but there's no vendor in sight (at least in the search area). Read the datapad near the arms dealer's stall to find that they've relocated.
Get outside the city and check your map- you'll they're located to the far west- just next to your potential outpost site. Check out the area to find a parked shuttle in the middle of a lake
Talk to the turian outside to automatically purchase a six pack for Kesh- you don't even need to spend money. This ends the mission, though if you drop by the Nexus later Wilma will tell you how it worked out. She'll also send an email.