The Wolf wrote:

> I'm sure some out there have had White Castle burgers.
>
> I suspect they mix chopped onion in with the patties. I wonder how that
> works because they are obviously shipped frozen.

Theyb don't mix the onion with the meat. They put a thin layer of
onions on the griddle, put the burger on top of that and the bread on
top of that. The onion flavor suffuses the meat and the fat given off
by the meat is likewise flavored by the onion. When they carefully (to
make sure none of that fat is lost) lift the burger and deftly flip it
over to put the top of the bun on top of the burger, it's all there,
tasty, greasy and wonderful.

Pastorio (shhh. Don't tell anyone.)

>
> I tried it once and it didn't taste very good. (freezing burger meat with
> chopped onion mixed inside.
>
> Must be a trade secret.