In 3-quart saucepan, bring potatoes and water to cover to a boil over high heat.
Reduce heat to low, cover, and cook until potatoes are very tender, about 20
Drain well and return to saucepan. Heat over low heat until all moisture is gone.
Mash with potato masher or beat with an electric beater.
Gradually beat in 1/2 cup milk, all but 1 teaspoon butter, the blue cheese, the
salt and pepper until smooth and fluffy. Add additional milk if necessary to make
potatoes soft and smooth. Taste and add additional salt, if necessary.
Transfer potatoes to serving bowl, and press remaining teaspoon butter into center.