You have a lot of collectibles to find for Yudia's Adventurer's Tome, and seven of those are cooking collectibles. You need to speak to NPC Hella, a Chef in the Noman Camp, to acquire a hint of where to find the ingredients needed to craft the Salted Food Box. Hella will mention that the item needed to craft this collectible is the Old Encavian Food Chest.
How to get Salted Food Box in Lost Ark
To get the Old Encavian Food Chest, you need to head to the Nevatia Ruins, located in Ozhorn Hill. If you have the Assembly Area Triport unlocked, this is the quickest way to get there.
Where to find Old Encavian Food Chest in the Nevatia Ruins
When inside the ruins, you need to head to the southeastern part. Just follow the map by pressing Tab to the location marked by the red square on the image below.
When you get to this location, you will find a few Mimics next to some boxes, and some other monsters will roam about this location, too. Kill them all, and look above the box on a wooden plank hanging precariously over a whole. This is your Investigation point. Interact with it and wait, and the Old Encavian Food Chest will be added to your Inventory.
Once the food chest is acquired, go back to Chef Hella in Nomad Camp, and turn it into Salted Food Box for 1,400 silver.
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