1 pound dried white beans (soak beans in water overnight)
1 meaty smoked ham bone or 2 ham hocks
3 fresh thyme sprigs or 1/2 teaspoon dried thyme
2 large carrot cut into pieces
2 medium celery stalks cut into pieces
1 medium yellow onion cut into small pieces
3 crushed garlic cloves
1 bay leaf
8 cups chicken stock
Salt and Freshly ground black pepper
Heat the olive oil in the soup pot. Add the onion, carrot and celery and cook over moderate heat, stirring occasionally, until the vegetables are softened, about 8 minutes. Stir in the garlic, bay leaf, thyme and cook until fragrant, about 2 minutes. Add the drained beans, stock, hame bone and bring to a boil. Simmer the soup over moderately low heat until the beans are tender, about 1 1/2 hours.
Discard the bay leaf, thyme and ham bone. Season the soup with salt and pepper and puree. Transfer to shallow bowls. Garnish the soup with black pepper, and serve with toasted sourdough bread.