Thank you everyone who has responded here, and on Facebook or Twitter, or via personal emails. Once again, I am amazed at the way these tools speed up intellectual interaction. Soon the days that I remember when you sent off a letter and waited weeks for response and even then could never gather up the kind of interaction that’s gone on here in the last 36 hours will be a distant memory. Please read all the responses. There’s lots of good stuff there.
Here’s a quick, first shot at a summary.
1. I change to griddle-baked instead of seared, thanks to Robyn Eckhardt’s comments.
2. There is a huge world of these very thin pastries that deserves to be better known. Very roughly they correspond to the world of Islam, including South India (though perhaps not northern Mughal India), Southeast Asia and possibly Horn of Africa.
3. The thin pastries seem to have been used either in tharid, the signature meat and bread dish of Islam (though surely at the upmarket end) or as pie casings or wrappers for savories or sweets (Charles Perry, Anissa Helou, Susan Ji-Young Park, Ammini Ramachandran et al).
4. They are put on the heated surface in a variety of ways:
By spreading a handful of pretty liquid dough
By tapping the dough on with the hand or a spoon
By spreading a thin batter
By flipping the liquid dough on with a cloth
By using a brush to spread the dough on (Adam Balic is one who speculates this is modern)
5. The heated surface may be a metal griddle (the commonest now, it seems), an upturned pot (I’m going to take the liberty of adding a photo that Paula Wolfert–I’ll take it down immediately if you have worries, Paula–sent Adam Balic in response to his forwarding Ammini’s video which, like the one in Ammini’s post, is black), or perhaps just stones.

6. That the technique is a tricky one, that it could have been spread by the migration of just a few skilled cooks.
7. That to make these pastries, you have to have either fine white flour or fine rice flour (missed that before, sorry). Prior to the end of the nineteenth century, these were reserved for the elite. Then new milling techniques made both much more widely available.
Note that I am assuming that all these techniques belong to a single family. In spite of Katy’s plea, I see no reason (with possible exception below) to think they were independent inventions. And for Nancy, who wonders why I talk about recent invention in relation to spring rolls wrappers, well, I’ve decided my default position is to assume something is recent until it is proven to be ancient.
Up for grabs.
1. When these doughs were invented. I’d now guess not before the (say) 9th or 10th century with the flowering of Islamic cuisine (pity we don’t know more about Sassanid). Quite likely, as Charles Perry says, “as part of the madness for the thinnest possible bread in medieval Moorish Spain and North Africa.” Certainly still there in Ottoman times. (By the way, Charles, I think Gene Anderson dates Chinese dumplings too late. I think they were there by the beginning of the CE).
2. What the connections, if any, with China are. Robyn Eckhardt believes the Chinese version of this pastry comes from Fujian (right, Robyn?) Agreed that there was massive Chinese migration from their and Canton to Southeast Asia. But do we have any evidence about the history of these pastries in South China? Or their connection, if any, with ping.
Finally, I find it interesting to compare this with the history of oven baked pastries in Europe (raised crust, short crust, puff pastry, etc. etc). All these depend on both fat and ovens.
The griddle baked pastries perhaps shouldn’t even be called pastries, if the European sense of pastries using fat is the norm. They are a dry pasta or bread.