Yeon Ji Yeong is a French chef with a cheerful yet strong personality. On the day she wins the best cooking competition in France, Ji Yeong suddenly ends up in the Joseon Dynasty. Instead of the Michelin 3-star bistro in Paris where she was offered the job as head chef, she meets the worst tyrant and has to prepare fusion royal cuisine for him.

Lee Heon is the king of Joseon and the owner of the restaurant where Ji Yeong works. Lee Heon, the worst tyrant who has wielded absolute power since becoming king, possesses an absolute sense of taste whose tongue is so sensitive that it can sense the changes in the taste of food depending on the weather. He accidentally meets the ghost woman, Ji Yeong, and falls in love with her food, so he lets her into the palace.

Kang Mok Ju is a greedy person who has been granted the favor of Lee Heon and has risen to the position of a long-time concubine, adding tension to the relationship between Yeon Ji Yeong and Lee Heon. Mok Ju, who has become the king's concubine due to her beauty and talent, is someone who hides her endless ambition for power.

Prince Je Seon is a member of the royal family of Joseon. Prince Je Seon, the most powerful political enemy of King Lee Heon, has a cruel nature where getting rid of people he doesn't like is easier than drinking water. After the death of his father, he acts as a vagabond to save his life, but he is always looking for a chance to drive out Lee Heon and become king.