In a subreddit dedicated to the Netflix series, u/the_indrawn_writer asked, "What was your favorite Geralt and Ciri scene this season? There were so many good moments between them ... the first is at the end of 2x01 when they have that talk by the campfire, and Geralt says he won't let anything happen to her. Ciri's little smile after hearing him say that was so endearing. It's the start of their trust and father-daughter bond taking form ..."
The scene in question comes from the final moments of Season 2, Episode 1, "A Grain of Salt." The original poster also mentioned a scene from Season 2, Episode 5, "Turn Your Back," in which Geralt reassures Ciri after she fails to complete an incredibly difficult obstacle course, and the unforgettable time in Season 2, Episode 7, "Voleth Meir," where Geralt protects Ciri by threatening Yennefer (Anya Chalotra).
While the comments offered other contenders or expanded upon some of the aforementioned scenes, the general consensus was that the original poster's first choice, the campfire sequence, was the perfect microcosm for their wonderfully portrayed relationship in Season 2. In brief, it starts with Geralt reprimanding Ciri for disobeying his orders to get to safety, then progresses to Ciri confessing her worry that everything she touches will die, to which Geralt offers advice that he finishes out with the above promise of protection.
It's action met by consequence, then a moment of calm reflection, and it really does encapsulates almost every interaction these two go on to have. It's also one of the many reasons why sites like Super Hero Era have labeled Geralt as one of the best modern TV dads.