Tomato Basil Soup with Tortellini

This soup is fast, easy, and of course, delicious!
2 Tblsp butter or margarine
1 medium-size onion, chopped
1 large carrot, peeled and chopped
4 cups regular-strength chicken broth
1 can (15 oz) tomato puree (or sauce)
1 can (15 oz) stewed tomatoes (optional)
3 Tblsp dry basil leaves or 1/3 cup chopped fresh basil
3/4 tsp sugar (this is to taste)
pepper
4-6 oz cheese tortellini (the frozen is better than the boxed)

In a 3 to 4 quart pan, melt butter over medium low heat. Add onion and carrot and cook, stirring occasionally, until both the onion and the carrot are sweet tasting and tender when pierced, about 30 minutes. Stir broth, tomato puree, stewed tomatoes, basil, sugar, and pepper into pan. Bring to a boil. Cover and simmer to blend flavors, about 15 minutes. Meanwhile, cook tortellini according to package directions in separate pan. With a slotted spoon, scoop vegetables and a little of the broth into a food processor, whirl until smoothly pureed. Pour vegetable mixture back into pan. Drain tortellini and add to soup. Heat till soup is steaming.