Heat oven to 300°F. Mix together flour, flax meal and salt. Mix together the wet ingredients, and add wet to dry. Mix until you have a smooth, elastic dough – not sticky. Add more flour if necessary. On a floured surface, roll out the dough to about 1/16" thick (you should almost see the table through the dough). Brush lightly with additional oil and sprinkle with kosher salt, if desired. Cut into squares. Bake on a parchment-lined pan for about an hour, or until they start to turn a little golden and harden. Crackers will harden further as they cool. Makes 3 dozen.