The Saint's Magic Power is Omnipotent (Manga) Vol. 2 (Kobo eBook)
Sei was summoned to a world in desperate need of a hero: a Holy Saint who could purify all evil. Unfortunately, she didn't quite make the grade as a Saint, but her talent for making potions has saved a lot of lives, not least of all that of a dashing, handsome knight-captain. Much to Sei's surprise, the supposedly frigid Winter Knight proves quite warm, and now the two have suddenly found themselves out on a date! With skills like hers, it won't be long before she's exploring all kinds of new magical frontiers.