Leiden Potato

Leiden Potato is an ingredient.

Source
Leiden Potato can be purchased from the Mini-mart at Hammerhead, the JM Market at the Prairie Outpost, the kiosk at the Wiz Chocobo Post, and Fallstar Foods and Furloch Farms in Lestallum for 20 gil. It can also be purchased from the shopping menu of the Regalia starting in Chapter 3. It can be earned as a reward for completing Takka's Scenic Delivery quest. It can be found at certain ingredient spots in the Longwythe Rest Area region of Leide. It can be sold back to shops for 10 gil.

Recipes
Leiden Potatoes are used in the following recipes:
 * Ace Hunter's Schnitzel
 * Battered Barramundi
 * Dish and Chips
 * Dry-Aged Tender Roast Stew
 * Fluffy Chiffon Cake
 * Garden Curry
 * Meat-and-Beet Bouillon
 * Veggie Medley Stew

Catalyst
Leiden Potatoes can be used as a catalyst in spells:

Trivia

 * The description is a reference to Samwise Gamgee's line in The Two Towers: "Po-tay-toes! Boil 'em, mash 'em, stick 'em in a stew."