Chongqing Street Food: Slow Roasted Yams

In wintertime, these barrels of slow-roasting yams show up on street corners. (She is holding an old-fashioned weight scale in her hand, I wish I hadn't cut it out):

The barrel is full of wood and some kind of clean burning briquets (is this the right word? I have no idea), and they put the yams on first thing in the morning. They slow roast all day, and are replaced as they are sold. Here's a close up:

Don't they look delicious? They caramelize naturally through the slow roasting, so they are sweet and tender inside. I eat them by hand like an apple with salt, no butter. The salt offsets the caramelized yam deliciously. And here's the kicker: a small one is about 1 RMB, or about 14 cents. How great is that? Here's what it looks like inside:

These are a different type of yam than the sweet potatoes available in the U.S. I think they taste better. I'll miss them.