Doumo, Suki na Hito ni Horegusuri o Irai Sareta Majo desu. (Novel)

From Cross Infinite World: “I want you to make a love potion.” The Good Witch of the Lake’s four-year crush ended in heartbreak with a single request from the object of her affection. Wanting to increase what little time she has with Royal Knight Harij, Rose sends him on a wild-goose chase for the ingredients but gets more than she bargained for when the grumbling knight starts visiting her every day to feed her? This is the heartwarming story of a shut-in witch and an arrogant, straitlaced knight whose romance starts from a love potion.