1. In a large bowl, sprinkle the yeast over the warm water, stirring to dissolve. Add the olive oil, sugar, salt, and oregano. Beat in 3 cups of the flour, then beat in the tomato paste. Gradually beat in the remaining flour.
2. Rub the palms of your hands with olive oil. Gather up the dough and shape it into a ball. Place the dough ball in an oiled bowl and turn it to coat it all over. Cover the bowl with wax paper then a towel. Set the dough in a warm place to rise until doubled, about 45 minutes.
3. Oil a 9-inch pie plate.
4. Punch down the dough and knead it several times. Shape the dough into a round loaf and place it in the pie plate. Rub the dough with olive oil, then let it rise in a warm place for 30 minutes.
5. Preheat the oven to 375 F.
6. Bake the loaf for about 50 minutes, or until browned. Remove it from the pie plate and cool on a wire rack.