A legendary Chef

The tale talks about a legendary chef capable of cooking dishes so legendary that it could tame beasts so powerful they could shatter mountains and rip the tides in half

The myth might have come from a time when the wyverns were more prevalent in the region they mostly lingered around the mountains though so I do not know what beast may linger in the ocean with such strength but non the less wyverns are sapient creatures they might have still had a snack and worked together but not tamed.

It is a story told to children and is a classic for people and dragons is very common knowledge basically anywhere in the region even in the mountains with wyverns.

There isn't much variation just the food depending on location and local food

For human it is not quite vital but still a common story like HTTYD or Harry Potter. Wit hthe dragons it is a uncommon but not rare story to be told but it is common on the outskirt of their territory thats where dracon and drakes heard it from and the wyverns are probably hearing it from the various explorer in the mountains

There are several book series that take inspiration from it like: I'm a master chef and I don't know how, Food among time, a beast delectable taste as well as others

There a several statues in locations such as cooking schools universities as well as often in restaurants they will have the equivalent of a lucky cat