Turkish Delight

Turkish Delight (or Lokum) is a sweet, made with starch and powdered sugar. It is often flavored with rosewater or lemon.

It was Edmund Pevensie's favourite sweet, and a magical (enchanted) version of it was offered to him by The White Witch. Like all of her magical food, it was highly addictive, making those who ate it want more and more, thus making them easy for her to control. With it, she was able to get information about Edmund's siblings from him, as well as learn about the Faun Tumnus who had helped Lucy escape, and easily trick him into betraying his family and attempt bringing them to her.

The Turkish Delight she had offered also made Edmund feel sick afterwards, quite possibly both from the effects of having eaten too much sugar, and because of the magical addictiveness of the Witch's food.

Trivia

 * Lokum is the original Turkish word for the sweet, which is derived from the Arabic words luqma(t), meaning morsel, and plural luqūm, meaning mouthful, used commonly in the Ottoman Turkish language.
 * The sweet, as it is known today, was invented by Bekir Effendi, who moved from his hometown Kastamonu to Istanbul and opened his confectionery shop in 1776.