Heat 2 tablespoons oil over medium-low heat. Add onions, sage and 1-1/2 teaspoons pepper, and cook from 5 to 10 minutes or until onions are soft. Stir occasionally. Let cool.
Pour lukewarm water into a bowl. Add sugar and stir until dissolved. Sprinkle yeast over top. Let stand for 10 minutes.
Combine 4 cups flour and 1/2 teaspoon salt in a bowl. Stir in cooled onion mixture. Once yeast is foamy, stir vigorously with a fork. Pour into flour mixture. Stir, then mix in remaining flour, 1/2 cup at a time, until dough is too stiff to stir. All the flour may not be used. Turn onto a floured surface and knead about 10 minutes.
Rotate dough in an oiled bowl until lightly coated with oil. Cover with greased waxed paper and a damp cloth. Let stand in a warm place until doubled in size, about 1 hour.
Punch down dough. Divide and form into 2 loaves. Place on a greased baking sheet. Lightly brush loaves with 1 teaspoon olive oil.
In a small bowl, stir 1 tablespoon pepper with coarse salt and rosemary. Sprinkle mixture over loaves. Let loaves rise, uncovered, for 30 minutes.
Preheat oven to 375 F (190 C). Bake loaves in centre of preheated oven for 40 to 45 minutes or until crust is golden. Remove from oven and let cool on a wire rack.