I'm currently travelling in Laos where my favourite local dish is called "larb" or "laap" (ລາບ in Lao, ลาบ in Thai).
When I described it to my Australian friend he said it sounded like a dish that was one of his favourites called "San Choi Bow" and described it as "either a southern Chinese or Vietnamese word for the spicy mince in a lettuce leaf".
I've been hunting on Wikipedia and there appears to be no English article though I have now found a Chinese Wikipedia article and the term does show up in a couple of articles on the English Wikipedia. There is lots of information on the Internet, I noticed especially from Australia. But the information is contradictory. Two Yahoo Answers questions about its origins give different answers with no further details: China, Thailand.
There's at least seven other spellings I could find, all combinations of "san" vs. "sang", "choi" vs. "choy", and "bau" vs. "bow".
To me this looks like Chinese but I couldn't find the Chinese characters and even if the dish has a Chinese name that doesn't mean it wasn't originally from a neighbouring country.
Could it be that "larb" is a Southeast Asian version of "sang choi bow" or is "sang choi bow" a Chinese name for their version of "larb"?
Sang choi bow, from the Chinese Wikipedia:
Squid larb in Thailand:
Pork laap in Laos: