Rosemary and Ginger Vegetable Soup

3 tablespoons olive oil1 large stalk fresh rosemary2 cloves garlic, minced2 tablespoons grated fresh ginger1 large yellow onion, diced1 green bell pepper, finely chopped1 red bell pepper, finely chopped2 carrots, cut into thin rounds8 ounces (about 2 cups) button mushrooms, stemmed and cut into quarters2 medium potatoes, cut into small cubes 1/2 small butternut squash, cut into small chunks4 cups vegetable broth1 cup crushed tomatoesSalt and freshly ground black pepper, to taste4 slightly stale sourdough dinner rolls, cut into cubesHeat the oil over a medium heat in a medium stockpot.Use a rolling pin to gently bruise the rosemary by rolling over it several times. Add the entire stalk to the pot. Add the garlic and ginger and cook, stirring frequently, 1 minute.Add the onion, green and red peppers, carrots, mushrooms, potatoes and squash, then saute 3 minutes, stirring often. Add the broth and tomatoes and bring to a simmer. Lower heat, cover and simmer 30 minutes, or until potatoes are tender.Taste and season with salt and pepper. Discard rosemary stalk. Ladle soup into serving bowls and stir one dinner roll, cut into cubes, into each.Serves four.