Creamy Potato Soup

1 garlic bulb, cloves separated (unpeeled)
2 cups reduced-sodium chicken broth
4 teaspoons olive oil
1 onion, chopped
pounds russet potatoes, peeled and cubed
1 bay leaf
2 cups low-fat (1.5%) or fat free buttermilk
1 (10-ounce) box frozen chopped green beans, thawed
1/2 cup chopped lean ham
Freshly ground pepper, to taste