Dissolve yeast in water. Stir in flour and salt. Knead on a floured surface until smooth (about 5 minutes). Divide into six balls and knead each until smooth and elastic. Flatten each to 1/4" thick and 4-5 inches in diameter. Cover with a damp towel and let rise for 45 minutes. Place upside down on a cookie sheet and bake at 500 degrees for 10-15 minutes, until light brown.