1. Place the cup of water, bread flour, sugar, salt, and yeast into the bread machine pan in the order recommended by the manufacturer. Select dough cycle, and press Start.
2. When the cycle has finished, place the dough in a greased bowl, turning to coat all sides. Cover, and leave it to rise in a warm place for about 30 minutes, or until it has doubled in bulk. The dough is ready if an indentation remains when touched.
3. On a lightly floured surface, roll the dough into a 16x12-inch rectangle. Cut the dough in half. Roll up each half of dough tightly, beginning at the 12-inch side, pounding out any air bubbles as you go. Roll gently back and forth to taper the end.
4. Place 3 inches apart on a greased cookie sheet. Make deep diagonal slashes across the loaves every 2 inches, or make one lengthwise slash on each loaf. Cover, and let it rise in a warm place for 30-40 minutes, or until it has doubled in bulk.
5. Preheat your oven to 375 degrees Fahrenheit (190 degrees Celsius). Mix egg yolk with 1 tablespoon water, and brush it over the tops of your loaves.
6. Bake for 20-25 minutes, or until golden brown.