Use one smallish sweet potato or yam per person.
Rinse and boil the sweet potatoes in their skins in a large saucepan until just done; still firm and not mushy or soft.
Remove the sweet potatoes carefully from the pan. (The skins should pretty much fall away. You can do this step several days ahead, if you like.)
The sweet potatoes will caramelize better if they are cool, so give them time!
Cut the sweet potatoes in half lengthwise, and then into chunks.
In an ample pan, over medium heat, make a caramel sauce out of equal parts light corn syrup and light brown sugar and 1 tablespoon butter -- 1/2 cup each of the syrup and brown sugar in this instance.
Let the sugar dissolve and become syrup-like in consistency, almost boiling.
Add the sweet potato chunks, being careful not to splash the hot caramel.
Allow the potatoes to sit for a moment without disturbing them to encourage the caramelization and then stir gently without breaking the potatoes, as they will break down easily. Pay close attention not to burn the potatoes as the syrup glazes them..
When the syrup is all but gone from the pan, turn off the heat and enjoy!
Be careful they are super hot!