Combine the yeast with 1/4 cup of the warm water. Let stand for about 5 minutes, or until creamy and foamy. If the yeast doesn't foam, discard it and start again with fresh yeast.
In a large bowl, combine 1 1/4 cups flour and the salt.
Add the yeast mixture, olive oil, and remaining 1/2 cup warm water. Stir until combined.
Gradually add enough of the remaining flour, about 1/4 to 1/2 cup, until the dough begins to pull away from the sides of the bowl. The dough should remain slightly soft and tacky.
Transfer the dough to a lightly floured surface and knead for about 8 minutes, adding only enough flour to prevent sticking, until smooth and elastic.
Divide the dough into two equal portions and shape each into a ball. Place in lightly oiled bowls, cover, and let rise in a warm place until doubled in size, about 1 to 1 1/4 hours.