In a small bowl, dissolve the yeast and sugar in the water. Cover and let set in a warm place for 15 minutes, or until yeast is creamy.
Place 2 1/2 cups flour in a large mixing bowl. Stir in the yeast mixture. Pour in the oil and stir until the flour is combined and a loose dough has formed. Turn the dough out onto a lightly floured surface and knead in the remaining flour as is necessary to keep the dough from sticking. Knead until smooth and supple, about 8 minutes. Lightly oil a large bowl, place the dough in the bowl and turn to coat with oil. Cover with a damp cloth and let rise in a warm place until doubled in volume, about 1 hour.
Divide the dough into twelve equal pieces and form into oval rolls. Place the rolls on a lightly greased baking sheet. Cover the rolls with a damp cloth and let rise until doubled in volume, about 40 minutes. Preheat oven to 450 degrees F (230 degrees C). In a small bowl, beat together egg white with 1 teaspoon water until frothy.
Brush the risen rolls with the egg wash and bake in preheated oven for 15 to 20 minutes, until golden brown.