Pour some of your discard onto the hot pan until it forms a perfect circle inside the edges of the pan. The amount will depend on the size of your hot skillet and the desired thickness of your flat bread
Turn the heat down and wait for bubbles to appear on the surface, and for the edges of the flatbread dough to start turning light brown
Flip onto the other side using a spatula. The first side should be lightly brown. Cook for an additional minute or a couple of minutes - this depends on the thickness of your dough.
Video
Notes
In my experience, it's better to turn the heat down and be patient during the last step. The flat bread will be fluffier if you can finish the cooking process on lower heat & a longer time rather than rushing it.