Navy Bean Soup (Potaje de Judias)

1 cup dried navy beans, rinsed in cold water, picked over, and left in water to cover overnight
2 1/2 quarts water
1 bay leaf
1 (2-ounce) piece salt pork, rind removed
1/4 cup pure Spanish olive oil
2 cloves garlic, finely chopped
1 medium-size onion, finely chopped
1/2 pound boneless smoked ham, diced
2 cups drained and chopped canned whole tomatoes
1 medium-size all-purpose potato, peeled and sliced
1/2 inch thick
1/4 teaspoon powdered saffron or
3 to 4 saffron threads, crushed
salt and freshly ground black pepper to taste
1/2 teaspoon ground cumin
1 cup shredded cabbage, optional
1 cup peeled, seeded, and diced pumpkin or Hubbard or butternut squash, optional
2 tablespoons finely chopped fresh parsley for garnish

Drain the beans, place them in a large saucepan with the water, bay leaf, and salt pork, and bring to a boil over medium-high heat. Reduce the heat to low and simmer, covered, until tender, 1 to 1-1/2 hours, adding additional water if necessary.

Meanwhile, in a medium-size skillet, heat the olive oil over low heat until fragrant and cook the garlic, onions, and ham, stirring, 6 to 8 minutes, until the vegetables are soft. Add the tomatoes and cook until thickened, about 10 minutes.

When the beans are tender, add the tomato mixture, potato, saffron, salt, pepper, cumin, cabbage, and pumpkin, and continue cooking another 30 minutes, adding more hot water if necessary. Remove the salt pork and discard. Mix well and serve garnished with parsley.