If I cover a sardine in pistachio cream, does it become Dubai chocolate?

Covering a sardine in pistachio cream won’t turn it into any kind of chocolate, Dubai or otherwise. Chocolate is a specific product made from cacao beans, and no amount of weird combinations will override that. You’ll just end up with a strange, probably unpleasant mix of salty fish and nutty cream. If you’re trying to impress someone with fancy food, maybe don’t start with sardines and call it chocolate.