Soften the yams by heating them in the microwave for a few minutes or boiling them in a pot of boiling water. Cool them off in a bowl of cool water and let them chill until you can comfortably hold them in your hand.

Turn your grill to medium-high. Spray your grilling rack or a sturdy piece of aluminum foil with nonfat cooking spray. Cut the yams into 1/4- or 1/2-inch rounds and arrange them in a single layer on your grill.

Brush the yams with olive oil or melted butter. For sweeter yams, top with brown sugar or a little maple syrup; for zestier yams, sprinkle with salt and pepper, a little onion powder and basil or, if you like the flavor, some rosemary.

Grill the yams for about 15 minutes, flipping them over about every five minutes to ensure that they cook evenly. If meat and other dishes crowd out the yams and you must grill them on a low flame, simply double the cooking time. Try to turn up the heat on the yams for the last few minutes of cooking to create a crispy, tasty edge.

Wash your yams, and then cut them in half lengthwise. Use a heavy cutting knife and watch your fingers because uncooked yams are hard.

Cut a square of aluminum foil that's large enough to fold around two halves of a yam. Spray the dull side of the foil square with nonfat cooking spray and lay two yam halves on top, flesh side up. Brush the skin with olive oil or place little squares of butter on top of the flesh.

Season the yams to your liking with sweet or spicy ingredients. Wrap the yams loosely and set them on the upper rack of your grill for about 1 ½ hours. Rotate the yam packages about every 30 minutes or so to ensure even cooking.