This page explains how to start and complete the What's for Dinner? side quest.
How to Start the Quest
Talk to Kiana in Lurelin Village, which is east of Faron Tower, to start the quest.
How to Complete the Quest
Kiana asks for Goat Butter and a Hearty Blueshell Snail. This type of snail can be found along Cape Cresia, which is southeast of the village. Goat Butter can be purchased in many places, such as Hateno Village, which is east of Hateno Tower.
Give the two ingredients to Kiana and she will give you rupees and a Seafood Paella.