1. Prepare dough. Then, lightly oil a baking sheet. After dough has risen twice in a bowl, knead it lightly on a work surface, flouring lightly only if dough sticks.

2. Shape dough into a rough cylinder. Cut cylinder into 3 equal parts.

3. Knead 1 part briefly and shape it into a cylinder. Roll cylinder back and forth firmly on the work surface until it forms a smooth rope about 20 inches long and about ¾-inch wide; when rolling dough, press it with your hands held flat and elongate the cylinder from its center to its edges. Taper the rope slightly at its ends. Roll the other 2 parts into ropes.

4. To braid the dough, put the ropes side by side, with one end of each closer to you. Join the ends farther from you, covering the end of the rope on your right side with the end of the center rope, and on top of that, the end of the left rope. Press joined ends together. Bring the left rope over the center one. Then bring the right rope over what is now the center rope. Continue bringing the outer ropes alternately over the center one, braiding tightly. Pinch each end. Tuck ends under-neath loaf. Set the braided bread carefully on the oiled baking sheet.

5. Cover the challah with a warm, slightly damp towel and let rise about 1 hour or until nearly doubled. Preheat oven to 375°F.

6. Brush risen loaf gently with beaten egg and sprinkle with seeds, if using. Bake in center of oven about 40 minutes or until top and bottom of bread are firm and bread sounds hollow when tapped on bottom. (Remove bread from oven before testing.) Carefully transfer bread to a rack and let cool.