Combine all the ingredients (except for the poppy seeds) in a large mixing bowl or the bowl of the stand mixer. Mix and knead until a soft and slightly sticky dough forms, about 6 minutes on a stand mixer and 8 minutes with hand.
Place the dough in a lightly greased bowl, cover and let rise for 45minutes to 1 hour or until the dough is doubled in volume.
Remove the dough from the bowl and place on a flat surface. Roll the dough into a long log -- it is best to roll from the middle outwards until the log is 30" long.
Cut 10" off one end of the log set aside. Arrange the remaining log as an upside down 'U' on a lined baking tray.
Lay the 10" length in a straight line down the middle of the 'U', with one end resting on top of the dough at the center of the curve.
Now braid the three strips of dough loosely making sure that the dough has room to proof.
Cover loosely with plastic wrap and leave in a warm place until doubled in size, about 1 hour,
Preheat the oven to 425°F.
Carefully remove the plastic wrap and brush the dough with milk or beaten egg and sprinkle with poppy seeds, if desired. Place the braid in the oven and bake for 8 minutes. Reduce the oven to 400°F, open the door carefully and turn the tray. Bake for another 8 minutes, then reduce the heat again to 350°F. for the last 8 minutes.
Remove from the oven and allow to cool a little before eatcing. This bread is best eaten as soon after baking as possible, but makes great toast the next day.