In a large mixing bowl stir together the flour, the salt, and the cocoa powder.
Add water and stir till the flour mixture is moistened.
Then use a wooden spoon to transfer the dough to a lightly floured surface.
Knead the dough 10 minutes or until smooth.
Place the dough in a clear plastic bag.
And store it in the refrigerator.
Before using the dough, check its consistency. If the dough is too sticky, knead in a small amount of flour. If the dough is too stiff, knead in several drops of water.