Hi Doctor,
If a flashback is not easy to do, why not just gave us two options that can be activate this way :
1/ Put a npc that allow us to exemplar to the level we want until we come and see him again.
2/ Add an option that can be used only one time per contact to reset all missions that he gaves and clears all the souvernirs / clues that come with.
That way, everyone will be able to do the Story Arcs and get the recipes they want.
It will also let us do the content we miss.