A much-beloved snack in fall and early winter. When I was a child, a vendor pushing a cart filled with blackened rocks and reddish-purple sweet potatoes would come around the neighborhood, chanting, "Roasted sweet potatoes! Rock-roasted sweet potatoes!" in a slow, time-honored cadence. If you started to get ready (asking parents to pitch in some cash) when you first heard the chant, the vendor would be near your house by the time you dashed out the front door. The man at the cart would dig through the rocks and find some big, beautiful sweet potatoes, wrap them in newspaper and hand them to his young customer. The warmth and the mellow smell were so rewarding, and needless to say the sweet taste was a big hit after running back to the house. Later the cart became a small truck and the chant was replaced with a recorded voice on a loudspeaker, but the melody was still the same. I wonder if those vendors are still coming around the neighborhood.
Yakiimo is also a favorite when family or friends gather to clean up the yard and burn fallen leaves, providing a perfect place to roast these fall treats.