Peel and quarter 1 medium potato. Cook, covered, in a small amount of boiling salted water for 20 to 25 minutes or until tender; drain. Mash with a potato masher or beat with an electric mixer on low speed. Measure 1/2 cup.
Instant Mashed Potato Rolls:
Prepare as above, except omit cooking the potatoes. Prepare packaged instant mashed potatoes (enough for one 1/2-cup serving). Substitute prepared mashed potatoes for the cooked mashed potatoes, and add an additional 1/4 to 1/3 cup flour.
Prepare as above through step 3, except do not let rise after shaping. Cover shaped rolls loosely with plastic wrap, leaving room for dough to rise. Chill for 2 to 24 hours. Let stand, loosely covered, at room temperature for 30 minutes. Uncover and bake as directed.