Mix together the flour, baking powder, and salt in a large bowl. Cut in the shortening to resemble cornmeal. Add water slowly, mixing with your hands to make a soft dough. You may not need all the water.
Knead a few minutes on a floured surface until smooth and elastic. Lubricate the top with oil, put back in the bowl and let rest, covered for 10 minutes.
Divide into small balls the size of golf balls and proceed to roll out into the size and thickness you prefer (or simply shape with your hands).
Cook on top of the stove over medium heat using a cast iron grill or heavy skillet until the top is slightly bubbly, then turn them over to brown the other side.