I've found a post taht says this food gives +10% HP, uncapped. I've not tested it myself though. No other stat effects have been recorded. There is speculation (probably due to the name) that it has an effect on Fishing, either skill or fish stamina. Anyone with any info, it would be great to hear from you!
Cooking (91)
Yield: Angler Stewpot
HQ 1: Prime Angler Stewpot
HQ 2: Prize Angler Stewpot
Fire Crystal
Stewpot Mastery (Key Item)
1 x Fish Stock
1 x Danceshroom
1 x Distilled Water
1 x Cotton Tofu
1 x Cibol
1 x Shungiku
1 x Shirataki
1 x Orobon Meat
Food Effects: (3 hours, All Races)
Group Food Effects
HP +10%
MP +10
HP Recovered While Healing +5
MP Recovered While Healing +1