Black Bean Pumpkin Soup

three 15 1/2 onunces cans black beans (about 4 1/2 cups), rinsed and drained 3 or 4 tablespoons sherry vinegar
1 cup drained tomatoes, chopped 1/2 pound cooked ham, diced
1 1/4 cup chopped onion 1/2 cup dry sherry
1/2 cup minced shallot 16 ounce can of pumpkin puree'
4 garlic cloves minced 4 cups beef broth
1 tablespoon plus 2 teaspoons ground cumin 1/2 stick unsalted butter
1/2 teaspoon freshly ground black pepper 1 teaspoon salt


Garnish:   sour cream and toasted pumpkin seeds.

In blender or food processor coarsely puree' beans and tomatoes.  In a 6 Quart heavy kettle cook onion, shallot, garlic, cumin, salt and pepper in butter over moderate heat, stirring, until onion is softened and starting to brown.  Stir in bean puree'.  Stir in broth, pumpkin, and sherry until combined and simmer, uncovered, stirring occasionally, 25 minutes, or until thick enough to coat a spoon.

Just before serving, add ham and vinegar and simmer soup, stirring until heated through.  Season with salt and pepper, garnish, and serve.