Mee Sum does four or five different fillings and they're all bomb.com. One of them is basically stewed pork in sweet and sour sauce. The color comes from FD&C Red. One of them is curry chicken. It's fuckin' curry chicken. One of them is beef stew. It could be goddamn Dinty Moore. I think their success comes from (A) the fact that they're softball big so you can get a proper amount of filling in (B) they do egg wash on the outside, and also some butter type stuff, and definitely sugar, and I'm not sure what else but by howdy they sweat the tops (C) the pastry is light. Hawaiian roll light. Hawaiian roll sweet, too, which allows you to contrast the filling.
I've done prosciutto in omelets and I gotta say I'd rather saute some black forest ham. It isn't as salty. But goat cheese goes with prosciutto, mozz goes with prosciutto, an aged cheddar goes with prosciutto, havarti sure as shit goes with prosciutto, iberico goes with prosciutto. I mean, it's basically pretense bacon once you cook it.