Boiling chilled chicken legs will take 40 to 50 minutes when simmered over a low flame. After the water is brought to a boil, it should then be turned down to a simmer. The chicken can be cooked from frozen on the stove or in the oven; however, cooking times are usually 50 percent longer for frozen chicken.
The Food Safety and Inspection Service (FSIS) recommends thawing chicken in the refrigerator, setting it in cold water or by microwave. Frozen chicken should never be cooked from start to finish in the microwave or a slow cooker unless it has been thawed first. Cooks should never refreeze thawed chicken unless it has been cooked fully.
They also recommend cooking chicken to a minimum safe internal temperature of 165 degrees Fahrenheit or 74 degrees Celsius, although many people prefer to cook chicken to a higher internal temperature. The temperature of the chicken can be checked by using a food thermometer at the innermost part of the chicken.
Raw chicken parts can be left in a refrigerator for up to two days before cooking and in a freezer for up to nine months. Once cooked, chicken can be kept in a refrigerator for three to four days or frozen up to four months.