Paprika on a yam? Yeah, yams are unbelievably sweet when exposed to direct fire, like candy sweet. But I'm talking about the Garnet and Japanese varieties, this might just be a less cultivated specie he found locally and just went with it.
Like the other reply to this comment, I think you're referring to sweet potatoes. As an aside, you're right about baked/roasted sweet potatoes. Their GI when baked is in the mid 90s!
Some salt, paprika, and butter makes a world of difference.