Lightly oil a medium bowl. Stir together water and yeast in a large bowl; let stand until foamy. Stir in oil. Add flour, hazelnut meal, sage, and 1 1/2 teaspoons salt; stir until dough forms. Turn dough out onto a floured surface, and knead with floured hands until smooth.
Transfer to oiled bowl, turning to coat. Cover bowl with plastic wrap, and set aside in a warm, draft-free place until dough has doubled in volume, about 1 hour. Divide dough into 2 balls.