Combine 1 cup warm water, sugar, and yeast in a large mixing bown; let stand 5
Combine salt, butter, and 1 cup water in a small saucepan; heat until butter melts. Cool to 105 to 115 degrees.
Stir butter mixture into yeast mixture. Add 2 1/2 cups flour; beat at medium speed of an electric mixer until blended. Add remaining 3 1/2 cups flour to make a soft dough.
Turn dough out onto a lightly floured surface; knead 10 minutes Cover and let rise in warm place (85 degrees free from drafts, 1 1/2 hours or until doubled in bulk.
Punch dough down, and divide into 16 equal portions Shape each portion into a 4 x 1 1/2 inch loaf-shaped roll. Place on greased baking sheets. Cover and let rise in a warm place, free from drafts, 35 minutes or until doubled in bulk.
Score tops of rolls with scissors ,making slashes 3/4 inch deep and 2 inches long.
Dissolve cornstarch in 1/2 cup cold water in a small saucepan ,bring to a boil. Let cool slightly. Brush each roll with cornstarch mixture. Bake at 375 degrees for 35 to 40 minutes or until rolls are golden brown.
Recipe by Ben's blog at http://whatscookingmexico.com/2008/07/11/conquering-yeast/