Ham and Bean soup

From December's issue of Cooks Country. We really really liked this recipe. However we did make this twice, once with navy beans and once with lima beans, and the time we made it with lima beans did not taste as good as when we used the navy beans.

2 tablespoons vegetable oil
1 pound ham steak , patted dry and diced
1 onion , chopped
3 carrots , peeled and chopped
2 celery ribs , chopped
6 garlic cloves , minced
4 cups low-sodium chicken broth
6 cups water
2 smoked ham hocks
1 pound dried navy beans , soaked overnight
2 teaspoons minced fresh thyme leaves
1/2 teaspoon pepper
3 tablespoons red wine vinegar
1. Heat oil in Dutch oven over medium heat until just smoking. Add diced ham and cook until browned, about 3 minutes. Add onion, carrots, and celery and cook until softened, about 8 minutes. Stir in garlic and cook until fragrant, about 30 seconds. Stir in broth, water, hocks, and beans. Bring to boil, then reduce heat to medium-low and simmer until beans are completely tender and soup is slightly thickened, 1 1/4 to 1 1/2 hours.
2. Remove hocks from pot. (If desired, let cool 5 minutes, then shred meat and add to soup.) Stir in thyme, pepper, and vinegar. Serve.
3. Make Ahead: This soup can be refrigerated for several days, but the beans will continue to soak up liquid. If the soup becomes too thick, stir in 1/4 cup water at a time until the consistency is to your liking. Simmer the soup over medium-low heat until it's hot. Serve.