Sprinkle a board generously with flour and turn the dough out onto it. Shape into a smooth ball and divide into 4 parts.
Form each into a round ball, using flour freely to keep the dough from sticking to your hands or to the board, but be careful not to work the extra flour into the dough. Roll out carefully, powdering any sticky spots with flour, until the dough is about 1/4- to 1/2- inch thick. Keep the shape round.
Using a large spatula, remove the round to a baking sheet that has been greased and floured. Prick the round all over with a fork; cut a hole in the center (using a small round cutter about 2 inches in diameter), and let rise in warm place about 15 minutes.
Bake in a very hot oven (450 degrees) for 10 to 15 minutes or until the bread feels firm when touched. The rounds should still bend when they are removed from the oven. Cool on a rack.
For the breads to become properly crisp, they must be dried after cooling. Traditionally, they were strung up on poles to dry. However, you may place them on the racks in the oven after the oven has cooled, and let them dry overnight or for about 6 to 8 hours.
To serve, break into pieces and spread with butter.