In winter we often find vendors stir flying chestnuts in a big wok with black sand, sprinkled with sugar. This particular one at Flower Market (花墟) is particularly rich. In addition to chestnuts, they have ginkgo (白果), peanuts (花生), and walnuts (合桃).
Not only that. They also have chicken eggs, quail eggs, and sweet potatoes () - both yellow and purple ones.
That time, I bought ginkgo. Yummy.