How Do You Cook Yam?

The process for cooking yams vary from place to place. Yams of African origin must be cooked (preferably boiled) to be fit for human consumption. Various natural ingredients in yams can lead to dideases if consumed raw.
The prdominant style of cooking in Western and Central Africa is called 'fufu'. Cooking some varieties of yam can be time consuming, involving days of crushing, percolating and boiling to remove poisonous constituents. Yams can be fried, boiled or crushed into a doughy substance.
In Phillipines, a variety of yam is eaten as a sweetened dessert . A deviation to the cooking rule is seen with Japanese mountain yam. It is taken raw and grated, after it is dipped in a vinegar solution for a brief period. The raw vegetable is tasteless and may be eaten as a side dish or added to noodles.

It depends, are they canned or fresh and how much.  Canned, drain half of the juice off, pour them into a glass baking dish, dollop butter or margarine on them, brown sugar or regular sugar (about a cup to 1 1 1/2 cup), sprinkle nutmeg and sprinkle cinnamon over the top of the yams.  Squeeze lemon juice over top of this and bake until the juices start to boil.  The juices should become somewhat sticky looking or what would be considered candied. If you use fresh yams, peel and cut into large dices, boil until a fork can pierce them, and prepare them as above.  If they get too mushy, you can always mash them up, put them in a dish and bake with marshmallows on top.  It's kinda trial and error.  You can't go too wrong.  Some find it easier to boil them, drain and season as above and do the marshmallow thing on top or put in in a pie shell and its a sweet potato pie (you would have to add a little milk, an egg and van. Flavor for the pie).