There are many people doing this in the small market now. But they stir-fry with iron sand. Although the color is very good, it feels very unsanitary (I am not alone). So, now many people are beginning to resist.

If you want to do it, I suggest you think of other ways to win the trust of consumers, instead of starting with hygiene as people do now. After all, chestnut is very nutritious and many people like to eat it. I feel that the prospects are still good.