Dissolve yeast in warm water in warmed mixer bowl. Add salt, butter, and flour. Attach bowl& dough hook to mixer, turn to Speed 2 and mix about 1 minute or until well blended. Knead on Speed 2 about 2 minutes longer. Dough will be sticky. Put dough in large greased bowl, turning to coat. Cover and let rise in warm place, free from draft, about 1 hour, or until doubled in bulk. Punch dough down and divide in half. Roll each half into 12" x 15" rectangle. Roll dough tightly, from longest side, tapering ends, if needed/wanted. Put loaves on greased baking sheets that have been dusted with cornmeal. Cover and let rise in warm place, free from draft, about 1 hour, or until doubled in bulk. With sharp knife, make 4 diagonal cuts on top of each loaf. Bake at 450F for 25 minutes, then remove from oven. Beat egg white and water together and brush each loaf with this mix. Return to the oven and bake 5 minutes longer. Immediately remove from baking sheets and cool on wire racks. Serve with your favorite spread such as herbed butter, garlic bread topping, etc.