Heat the oil in a medium saucepan and saute the onions, celery, bay leaves and black pepper until translucent. Add the clams and mix to combine.
Add the potatoes, wine, parsley, clam base and a quart of water to the pan and cook until the potatoes are tender.
Add the cream and milk and bring to a boil, about 10 minutes.
Meanwhile, make the roux: Melt the butter in a heavy-bottomed medium saucepan. Add the flour and cook, whisking continuously to prevent burning, until the mixture is pale golden with a nutty aroma, about 7 minutes.
Whisk the roux into the soup and bring to a boil. Add salt to taste.
Serve the clam chowder with oyster crackers.
This recipe was provided by a chef, restaurant or culinary professional. It has not been tested for home use.