Yams, which are usually called sweet potatoes if sold in the United States, take approximately 10 to 30 minutes when boiled and 40 and 50 minutes when baked. The disparity in time depends on whether the cook wants the yams to be completely soft or just soft on the outside with some texture remaining in the middle.
For home cooks who are pressed for time, yams can also be cooked using a microwave as long as the skin on each yam has been pierced several times and then cooked for up to 10 minutes. Boiled yams should cook on medium-high heat, while baked yams should roast at 425 degrees Fahrenheit. Similar to sweet potatoes, yams can be made into pies, served candied with marshmallows or cut into strips and made in an oven.