1. If working by hand: In a medium-sized bowl, mix together the salt and the flour. Make a well in the middle and add the warm water. Mix with your hand or with a spoon until you can gather it together into a dough (depending on your flour, you may need a little extra water or a little extra flour to make a kneadable dough). Turn out onto a lightly floured surface and knead for 8 to 10 minutes. If using a food processor: Place the flour and salt in the processor and pulse to blend. With the blades going, slowly pour the water through the feed tube. Leave the machine on for about 15 seconds after a ball of dough forms, then turn the dough out onto a lightly floured surface and knead briefly.
2. Cover the dough with plastic wrap and let stand for 30 minutes or for up to 12 hours. (The longer the dough stands, the more digestible the breads and the easier they are to shape.)
3. Divide the dough into 8 pieces and roll each into a ball under your lightly cupped palm. Place some flour on your work suface, dust your palm with flour, and flatten each ball in the flour, pressing both sides into the flour in turn.
4. To shape the breads, work with one piece at a time (leaving the others lightly covered). Working on a lightly floured surface, and without turning the bread over, flatten it with a rolling pin, rolling from the center outward, with light strokes, and rotating the bread slightly between each stroke, until the bread is 7 to 8 inches (17 to 20 centimeters) in diameter. Repeat with the remaining 7 breads, keeping the others loosely covered. Do not stack the rolled out breads; if you don't have enough counter space for the breads, roll out just a few and begin cooking, then roll out the others as the breads are cooking.
5. Heat a cast-iron griddle or skillet over medium-high heat. Rub the surface with a well oiled cotton cloth or paper towel. When the griddle is hot, place a chapati top-side down on the griddle.
6. Let it cook for only 10 to 15 seconds, then gently flip to the second side. Cook on the second side until small bubbles begin to form, approximately one minute. Turn the chapati back to the first side and finish cooking (another minute approximately). At this stage, a perfect chapati will start to balloon. This process can be helped along by gently pressing on the bread. The bread is hot, so we find the easiest method is to use a small cotton cloth or a paper towel wadded up to protect your finger tips. Gently press down on a large bubble forcing the bubble to extend itself wider.
7. If the bread starts to burn on the bottom before it has ballooned, move the bread (with the help of your paper towel) across the skillet, dislodging it from the point at which it is beginning to burn.
When you are satisfied with your chapatti, remove it and wrap in a clean towel. Continue to cook the other breads, stacking each as it is finished on top of the others and wrapping it to keep it soft and warm.