Kale and Chickpea Soup

2 garlic cloves, chopped

1 Turkish or 1/2 California bay leaf

1 teaspoon salt

1/8 teaspoon black pepper

2 tablespoons extra-virgin olive oil

1 large boiling potato(3/4 lb), peeled and cut into 1/2-inch pieces

3/4 lb kale, stems and center ribs cut out and discarded, then leaves very finely chopped in a food processor (4 cups)

3 1/2 cups reduced-sodium chicken broth (28 fl oz)

2 cups water

1 (14-oz) can chickpeas, rinsed and drained

1/4 lb Spanish chorizo (cured spiced pork sausage), casing discarded and sausage cut into 1/4-inch dice (1 cup)