2 tablespoons butter or oil

1 large onion -- finely chopped

3 stalks celery -- finely chopped

1 pound potatoes, peeled -- cut in 1/2" cubes

1 pound firm-fleshed white fish fillets(like cod) -- cut

in 1 1 /2" chunks 2 cups fish stock

or clam juice 1 cup cold water

1 bay leaf

1/2 teaspoon dried thyme

1 cup milk (up to 1 1/2) -- * see note

1 cup fresh or frozen corn kernels -- thawed

salt -- to taste white or black pepper -- to taste Optional Garnish: butter -- cut into pats

serves 4

*Make it as rich as you like by stirring in either milk, half and half, or heav y cream at the end. You can also gild the lily by floating a pat of butter on top of each portion.

Heat the butter in the cooker. Saute the onions until soft, about 2 to 3 minut es. Toss in the celery, carrot, and potatoes, and saute an additional minute. Add the fish chunks, stock (watch for sputtering oil), water, bay leaf, and th yme.

Lock the lid in place and over high heat bring to high pressure. Adjust the he at to maintain high pressure and cook for 4 minutes. Reduce the pressure with a quick release method. Remove the lid, tilting it away from you to allow any excess steam to escape.

Remove the bay leaf and stir in the milk, corn, parsley, and slat and pepper to taste. Simmer until the corn is cooked and the chowder is hot. Transfer to a serving tureen or individual bowls and top with additional butter, if desired.