After taking an authentic Thai cooking class in Thailand, it was interesting to learn how much sugar they use in stir fry to neutralize spice. The sugar source they use is palm sugar and palm sugar paste. However, since I like spicy, I did not add any sugar. They gave us the recipes, check the link below. Very tasty! Please note that the oyster sauce also includes some sugar in the pre-maid sauce you buy from stores. Enjoy!