Heat water with a pinch of salt till it comes to a rolling boil. Add the rice flour and reduce the heat to low. Mix well using a wooden spoon and turn off the heat. The rice flour will clump, make sure that there are no large pockets of dry flour and all the water is absorbed. Cover with a lid and let it rest for 10 to 15 minutes until warm enough to touch.
Knead well using your hands. If needed add a few teaspoons of warm water or extra flour as necessary. Form into a soft and smooth dough. Place the dough in a closed container or cover with kitchen towel.
Pinch off a lime sized piece from the dough. Roll it into a smooth ball. Dust the work surface with rice flour and place the ball of dough. Dust the top with more rice flour. Using a rolling pin roll the dough into a thin flat disc.
Transfer to the hot skillet and cook over medium high heat for 20 to 30 seconds or till the pathiri turns slightly opaque (dry). Flip land let it cook for another 30 seconds before flipping again. If the pathiri does not puff up on its own press down gently with a spatula or clean kitchen towel to help it bubble up.
Transfer the cooked pathiri into a container. Cover with a kitchen towel and close the lid.