Preheat the oven to 325°F. Prick each yam several times with a fork and set in a parchment paper-lined baking pan. Bake until just tender, about 60 minutes.
While the yams bake, set the cranberries in a small bowl, cover with warm water, and let stand 30 minutes to plump up, and then drain well.
When the yams are baked, remove from the oven and cool to room temperature.
While the yams cool, place the pears in a bowl and toss with the lemon juice. Melt the butter in a skillet set over medium heat. Add the onion and pear and saute until tender, about 5 minutes. Remove from the heat, mix in the cranberries, cinnamon and nutmeg, and then set mixture aside for now.
When the yams have cooled, line a baking sheet with parchment paper. Carefully pull or cut off the skin on each yam. Slice the yams, at a very slight angle, into 1 1/2" to 2" thick rounds and set on the baking sheet. Slice the goat cheese, widthwise, into thin slices, and then set one or two slices on top of each yam round. Now mound some of the pear mixture on top of each yam round.
Drizzle each yam round with a little maple syrup and balsamic vinegar, and then season with salt and pepper. Bake the yams, uncovered, in a 325°F oven for 20 minutes, or until heated through.
Options: For a stronger cheese taste, instead of goat cheese, top the yams with a creamy style of blue cheese.