Corn Chowder with Roasted Jalapeño and Parsley Purée

5 fresh jalapeño chilies

1/4 cup olive oil

1 1/2 tablespoons fresh lime juice

1 tablespoon water

1 garlic clove, minced

1 cup packed fresh parsley leaves For the chowder:

1 onion , chopped fine

2 ribs of celery , chopped fine

2 tablespoons vegetable oil

2 cups chicken broth

2 1/2 cups water

1 1/2 pounds boiling potato es

1/2 pound ham steak if desired, cut into 4 cups fresh corn kernels including the pulp scraped from the cobs (cut from about 6 ears of corn)

2 teaspoons fresh thyme leaves, minced