Where do I find meat for the hidden merchant?

There seems to be a random Chokobo that you can kill for raw meat, but he wants it cooked. Still trying to figure out how to cook it. I got the encounter with the chokobo just north of the first town.

Edit

After killing a chokobo in the northern plain, you'll have to talk the the lady near the well in Aogai (the one with a roof, not the one near the expensive merchant and the overactive kid) so she'll cook it and you'll be able to give it the to merchant. It will give you :

An extra heart (health)