Don't know if it's a thing is asia, but the steam bun sandwich thing with random ingredients has been in the US for a while now. It got trendy again for a little bit once the rice burger bun(which was a thing in Japan) died down a bit. Oddly enough most places I see either tend to be Korean.At first I thought you meant a katsu sandwich, but I rewatched the video and it's a steam bun. That's pretty weird.
Tempura udon is also incredibly common, and yeah it gets soggy.I was not aware of this! Thanks for pointing it out.
Getting the absolute perfect distribution of fat, having fewer possible foodborne illnesses, and at a cost that makes sense? Absolutely sign me up.I wish fake meat was so cheap that they could substitute it for real meat and no one would know the difference. I'd buy that shit if that were the case.