This story is super hard to follow, it feels like it makes huge assumptions on the readers detailed familiarity with royal family structures and inter-relations, except how they work in this story is all messed up, which just leaves the reader going... uh... What?
Also, in what world are the second born in noble families expected to become freaking chefs?! That is so messed up on so many levels, especially when the first "serious" topic they discuss is on the status of an active large scale military engagement that threatens a large number of their citizens. In practically every noble/royal structure it's exceedingly common for them to take up military endeavors, but in spite of huge military conflicts in this world, they all go simmer soup... wtf?
On the subject of that "serious" conversation, the suggestion the MC makes also makes no sense. They are talking about the fortress being under siege, and her point is that people may want to leave if peoples crops fail (due to tainted water), causing the gates to opened... Has everyone forgotten the meaning of the word "siege"?! NO ONE LEAVES A SIEGE!! I mean seriously, wtf. The whole point of a siege is that you are isolating and forcing the opponent to surrender since they CAN'T LEAVE! They are cut off from people, supplies, and re-inforcements.
The author clearly wants to write a lovey dovey cooking story. However they are clearly putting it in a setting they don't understand and are ill equipped to work in. They should have just made it occur in the present day and been happy with that.