Hell's Kitchen
Once the war ends and Thane is in the tavern, and you have cooked at least 5 of Parif's dishes, talking to Thane will have him mention how he misses cooking, and wants to become Parif's apprentice to cook and be useful to the tavern.
Parif puts Thane to the test to become his apprentice, he'll need your help to cook one good dish in one week, before Parif gets back, to show him he knows at least what he is doing in the kitchen.
The quest involves hunting for several items (not just ingredients…) and also finding some taste-testers to gather useful information: if, at any point, you say that "you can't find a volunteer", you and Thane will fail; you can volunteer yourself, but each dish grants you one permanent malus, so you'd better think twice about doing that…
Check the ingredients map or the tab with the various items at the bottom of the guide if you don't remember where to find something. The 3 dishes are:
- Slime fish jelly: requires 2 grass carps and 5 slime jewels, reduces your max HP by 19.
- Cold appetizer: requires 2 cabbages, 4 seaweeds, 3 bottles of rum, reduces your max MP by 21.
- "I don't know what it is": requires 4 shiitake, 6 raspberries, 2 iron ores and 3 ectoplasms, reduces your max lust by 10.
The most fun part of this quest is the fact you can ask pretty much any npc in the whole game to taste test each dish, from the people in the tavern (bathhouse included) and the tribes to the ones in the cave, the city and the first painting. The only 3 taste-testers, though, are Snow, Chet (by paying 1000 coins…)* and Axel, but only if he liked you more than Nauxus at the end of the war (or both him and Nauxus having 3 suspicion points).
*Ask Snow before Chet! If you ask Chet first, Snow will refuse the next dish, even if you won't have to pay the former 1000 coins. Also, this means that, if Axel doesn't like you enough, you will have to taste at least one dish, so do choose your malus carefully…
Finding taste-testers for all the 3 dishes means Thane will be successful (kinda), and has quite the good reward: 3 level up points, and a new dish that grants 2 level up points the first time you cook it, and has outstanding healing properties (but has demanding ingredients), and potentially new recipes as Thane improves his cooking skills. Failing it only gets you 1 level up point (0 or 1 dish tested), or 2 level up points (2 dishes tested), and no new recipes.