Seeking Legendary Book!

Seeking Legendary Book! is the eighteenth Trouble Center mission in Paper Mario: The Thousand-Year Door, initiated by Zess T.

Mission
Mario and co. must head to Zess T.'s house in Rogueport Square, and she will tell him of a legendary cookbook hidden in Creepy Steeple. Mario must head to the entrance of said location and use the Roll ability to enter a secret room with the cookbook. Returning it to Zess T. rewards Mario with a Honey Shroom, as well as the ability to receive and use items cooked from two different ingredients, as opposed to one.

In-game description

 * "I want you to find the legendary cookbook for me! It's in a pretty scary place, so there's no way an old gal like me could get it alone! Please come to my house in Rogueport Square for details!"