I like to put one layer of whole, sliced or stabbed yams and/or potatoes in a pyrex pan. I then cover the bottom of the pan with water. I cover the pan tightly with foil and stick it in the over. Sliced potatoes can be baked at 350-375 degrees Fahrenheit (180-190 degrees celsius . Whole potatoes should be baked at 375-425 degrees Fahrenheit (200-220 degrees celsius). When the potatoes are whole it can take a really long time, up to two hours. So I recommend to at least stab them a few times or cut them down the middle. Check on the potatoes periodically until they reach the softness that you like. Each time you check also make sure the water doesn’t all bake off or the pan will burn.
Serve the potatoes/yams with your favourite toppings. My family’s favourite toppings are sour-cream, butter/earth-balance, and tehini sauce (see "Tehini Sauce Recipe").