Combine flours in a large mixing bowl. Reserve 1 cup; set aside. Add undissolved yeast, sugar and salt to flour in mixing bowl and mix well.
Heat water, milk and shortening to 120°F to 130°F. Add warm liquids to dry mixture; mix well until well blended. Gradually add enough reserved flour to form a soft ball of dough. Turn dough onto floured surface.
Knead (with reserved flour) for about 10 minutes or until dough is smooth and elastic. Cover; let rest 10 minutes.
Divide dough in half. Roll each half to a 16 X 10-inch rectangle. Roll up lengthwise, as for a jelly roll. Grease baking sheets; sprinkle with cornmeal if desired. Place each loaf on baking sheets. Cover; let rise until double, about 30 to 40 minutes.
Preheat oven to 400°F. Brush loaves with cold water. Slash top of loaves diagonally about 1/4-inch deep and 2 inches apart. Bake for 15 minutes. Brush again with cold water. Bake for 10 minutes more, or until golden brown. Cool on wire racks.