You cook a sweet potato by thoroughly scrubbing the skin, piercing it several times with a fork, and roasting it in an oven at four hundred degrees Fahrenheit for roughly forty five minutes. If you are short on time, you can also microwave a pierced sweet potato on high power for six to eight minutes until the inside flesh is tender. Boiling cubed sweet potato pieces in a pot of salted water for twenty minutes is another great method for making smooth mashes. Selecting the right cooking technique ensures your sweet potato turns out delicious every time.