A couple of different ways of doing sweet potatoes.

These sweet potatoes were sliced 1/2 inch thick and then boiled until mostly cooked.  They were then brushed with a molasses glaze and finished on the grill.  Good stuff.  Shown here with "pork chop calzones".

Another great way to do sweet potatoes is to just throw them whole directly into the hot embers for about an hour.  The outside completely chars and when you cut them open, the inside is nicely done but bits of that char and smoke from the fire add a nice extra touch.  Served with cinnamon maple butter helps too.