I don't have an exact recipe, as I adjust depending on the number and size of sweet potatoes I use, but I make a casserole as a side dish, for special occasions, that according to family and guests is delicious. Myself I'm not that keen about sweet potatoes, but this is OK.

3 or 4 sweet potatoes or yams
1 med. to large onion finely chopped
4-5 strips of bacon cut into small pieces
dab of butter
1/4 C of demararra sugar packed or cut back slightly on the sugar and also add pure maple syrup to the mix
1 tsp of cinnamon
1/2 tsp of nutmeg
Salt to taste

Peel, dice and boil sweet potatoes until soft, then mash with butter. Meanwhile, sautee bacon and add onions and cook until mixture is golden. Add onions and bacon to drained and mashed sweet potato, add sugar, maple syrup and seasonings, turn out into casserole dish and bake at 350 for approx 30 minutes. Good one to do the day before and reheat. Its better IMO the second time around.