12 minutes ago, Annie_H said:Something called 'red cooking' ,and a fermented red rice used for color.
'Red cooking' in China is 红烧 (hóng shāo) and does not involve red rice. It simply means braised in in soy sauce - a Shanghai specialty. It certainly doesn't involve red food coloring. I wouldn't even know where to buy that.
Red rice yeast is used in good quality char siu.