There are a few parts of crab rangoon that give away its absence of "realness." The first is its fundamental fixing: cream cheddar. Crab rangoon is said to start in either British Colonial Burma (Myanmar) or Trader Vic's, an American tiki bar eatery. Cream cheddar isn't a fixing frequently found in Myanmar, so the case for that beginning story isn't exceptionally solid.
The other piece of information is in the name. "Rangoon" is the thing that the British called the capital of Myanmar. Today it is by and by called by its unique name, Yangon, which the British misspoke.