The Girl's Notebook is an item from The Legend of Zelda: Breath of the Wild. It acts as a cook book and contains a single recipe for Pumpkin Stew. It is found in the house with a Goddess Statue at Hateno Village. Link can reach it via a ladder near the beds of Reede, Clavia, and Karin.
"For a secret recipe that'll surprise even the most knowledgeable of dads, start with some fortified pumpkins. Throw in some Tabantha wheat to give the stew a nice wheaty flavor, then let some fresh milk and goat butter simmer. And there you have it! A tasty pumpkin stew!"