Contract: Mysterious Tracks - Velen
Quest Giver: Lindenvale Notice Board
Other Requirements: N/A
This quest can be started one of a few different ways, the two most common are by accepting the notice from the Lindenvale Notice Board or by speaking with the Hunter (pictured above). Alternatively you could also start this quest by investigating the tracks near the cave that's involved in this quest.
After speaking to the contract issuer head to the location marked on your map/compass. Here you will find a slain pack of wolves as well as foot prints leading away from the area that you will need to follow. They will lead you to a tree with fur on it. Inspect it to pick up the creature's scent then follow that to the cave's entrance.
You won't be able to reach this entrance so you'll have to find the other way in, which is a tad bit to the north of where you are now. Alternatively you can skip all of the detective work for this quest and go right to the cave entrance to get the quest updated.
Inside of the cave you will have to use your Witcher Senses to look around. Prints on the ground, blood and tuft of fur inside of the fiend's mouth are all of the things you'll have to examine. Geralt will come up with the idea to lure the monster back to this cave and your quest will update.
Go into your Alchemy tab and make the Chort Lure, you may have done this in the past in which case just go into your inventory and equip it. You can find it under the Quest Items tab in your inventory - if you're having trouble locating it use my screen shot below for guidance. To use this item you'll have to bind it to your quick list menu and use it as you would other quest items (same menu as your Signs).
Once you use the Chort Lure at each of the different locations return to the cave and prepare for the boss fight. Much like all of the enemies throughout the game you will want to focus mostly on dodging. Hit the Chort a few times then start dodge rolling out of the way to avoid its attacks, rinse and repeat.
Chort Weaknesses: Relict Oil, Devil's Puffball, Quen