Not chinese, but you sure there was a coating? Basic stir-fry process is
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Deepfry or blanch everything for however long you need to cook the insides
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Set aside for however long
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Throw some of the oil a hot pan with garlic and other aromatics, cook like 30 seconds
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Throw pre-cooked ingredients in, crank heat to max, making sure not to burn anything, but still let it cook.
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Throw in salt, sugar, soysauce, whatever.
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Add water+cornstarch mix
If you don't pre-cook, you have to use lower temp and everything spends more time in cool oil and makes the whole thing greasy.