My daughter needed a pot luck item for a Thankgiving dinner tonight with about 19 friends. She loves sweet potatoes, peeled and cubed them, roasted in a 400 degree oven on a cookie sheet. I find that about 3 sweet potatoes will fit per cookie sheet. Keep them in a single layer, they will brown nicely and not get mushy. (I also love Butternut Squash and/or Beets roasted in this same way.)
Make sure you use a little olive oil so they do not stick. After 45 minutes, they will be perfect. Salt and pepper to taste and I always like to add a bit of freshly grated nutmeg.