San Francisco Sourdough Bread

INGREDIENTS

• 4 3/4 cups bread flour
• 3 tablespoons white sugar
• 2 1/2 teaspoons salt
• 1 (.25 ounce) package active dry yeast
• 1 cup warm milk
• 2 tablespoons margarine, softened
• 1 1/2 cups sourdough starter
• 1 extra large egg
• 1 tablespoon water
• 1/4 cup chopped onion