Mash potato and set aside.

In a large bowl, combine lukewarm potato water (105-110°F). Dissolve yeast in water and allow to stand for 5 minutes.

Beat in egg, butter and mashed potato. Stir in as much of the flour as is needed to make a soft dough.

On a lightly floured surface, knead dough for 5 minutes. Place in a buttered bowl, turning once to coat dough surface with butter to prevent dough from drying out. Cover and let rise in a warm place until doubled in size (60-90 minutes).

Punch dough down and roll out to a 1/2-inch thickness; cut out 3-inch circles with a biscuit or cookie cutter.

Place rounds on a greased baking sheet and allow to rise until double in size (30-60 minutes).

Preheat oven to 350°F.

Bake for 18-20 minutes or until golden. Cool on wire rack.