Since sweet & sour (something) was mentioned earlier, we can go into the history of it for a better understanding (and to cement the fact that yes, authenticity is somewhat a capture of a moment in time as food evolves, to better understand the frame of reference). Yes, sweet and sour is not Chinese American, faux Chinese. There are non traditional (re: shortcut driven) versions for sure.
Back in the old days, fatty pork was cheap and lean pork was expensive. In order to make fatty pork (e.g. belly) easier to eat, Cantonese Chinese came up with the idea of starch coating pork cut a certain way, deep frying, drain the oil, then cooking a separate mixture of a sauce that is sweet and sour, then cooking both together with carefully controlled wok temperatures and searing. This made the pork less filling but enough acidity and some sweetness to stimulate appetite.
As the economy improved over time, people became more health conscious, and nowadays even the most traditional of Cantonese restaurants, sweet and sour pork cuts of meat were shoulder cuts (similar to that used for Cantonese char siu). The sweet and sour sauce flavors would come from a mixture of pineapple, ketchup, vinegar at the absolute bare minimum. The old school traditional places would make the sweet and sour more complex and nuanced, by also adding fresh and dried hawthorns, perhaps a sour plum (think Japanese umeboshi but different), and adding some sugar for adjustment. The fastidious places may switch it out depending on the season, replacing pineapple when not in season with pickled ginger. There is one very well known restaurant in Hong Kong that uses three types of hawthorn for the sauce (fresh berry, dried sticks, and flakes - like the candy) and yet I believe goes back to pork belly. The criteria (by eaters) for a plate of sweet and sour pork would be the ideal amount of wok breath/wok hay, fried pork that is not greasy, but even with the sauce coating the exterior is crunchy and the interior almost fluffy like, with a delicate balance of sweet and sour flavors from the sauce as well as the textures from the other ingredients. There should be no excess sauce smothered all over the plate (e.g. the cornstarched thickened varieties you find in many places abroad), though it is ok if there is a very shallow pool of the sauce that sinks to the bottom. And finally even when eating halfway through, the dish is still very respectable and tasty.
Fast forward to today, there are maybe 15 restaurants that do what locals, food writers consider traditional sweet and sour pork (where a lot of work is put in) in Hong Kong, perhaps more if you include the neighborhood joints that do it decent, but not at the level of those 15 or so that would satisfy the extreme nitpicky and traditionalists. Plenty of other shortcut quick fix places of course.
Then you have the Chinese American renditions in various parts of the world (e.g. Chinatowns).
You have Korean Chinese variants (tang su yuk), and sugar vinegar spareribs which are completely different in Shanghainese cooking. And Japanese Chinese su-buta where the taste is less nuanced, but also can be delicious in its own right.
Oh by the way, the even more original Cantonese sweet and sour pork, was sweet and sour spareribs apparently. Meat and fat around the bones. Think pork spareribs black bean sauce dim sum variety, but cut into bigger pieces. Pork/pork belly was substituted without bones, to make it easier for Westerners.
All of this information was compiled from various Hong Kong media / print sources (all credible), and one archived academic university research paper (also from Hong Kong).
So of all versions listed above that originated in Hong Kong and if we were to include overseas versions, which versions are authentic? Assuming the informational sources are authentic as well?