headcanon that as Neph is now free to start telling the party more about like his childhood and what it was like for him growing up, once Kieran catches onto the fact that Neph hasn't really been able to try very many different foods (aka the palace picked the meals for servants) and has only started trying new foods after running away, everytime they pass like a food stand while they're traveling he's just like. hey does that look good? and if the answer is yes he's already over there buying some for at least Neph, and probably the rest of the party if they asked.
like yeah Neph has technically had the time to try different foods, however he has not always had the money to do so. Kieran however, has very deep pockets. pockets so deep in fact that his entire cloak is just one big pocket. I think Kieran keeps a mental note of what Neph seems to like and not like when they try stuff, so he can point out things he thinks Neph would enjoy.
At some point Neph might try to be like, "oh no you really don't have to! its fine, its really not that big of a d-" and Kieran is just like "girl, shut up and take the damn croffle"