Lay them out on a parchment or foil lined sheet pan, mostly in one layer. A little overlap is fine, but do not crowd too much.
Sprinkle with generous pinch salt and cracked pepper.
Roast 20 minutes in the oven. Scatter with pecans and drizzle with a little maple. Gently mix and then return to the oven for 10 more minutes, or until edges begin to caramelize and yams are tender. Place on a platter or baking dish, cover loosely with foil and keep warm until serving.