Ok, time to throw my disturbing hat into this very inviting ring.
Tinies would probably just taste like people, in most settings anyway, not counting the weird stuff. Maybe if you wash them in some flavored body soup, that would add to the flavor?
But for me personally, the flavor is not the point of eating a tiny. It’s the reinforcement of the power dynamic, I am big, and they are small. The dehumanization of being nothing but food for some sadistic fucker to get off eating, not even being enough to fill them up, so enchanting~. Hearing them scream and beg inside of my mouth while they struggle pointlessly, tasting their tears and blood, not that I would nibble too hard, mind you~. And I would definitely swallow them alive, even gulp down some air, so they don’t pass out from lack of oxygen, making them be awake and wear when my body breaks them down to nothing~.