Rustic Fish Chowder

Ingredients

• 1/4 cup butter, cubed
• 1 small onion, finely chopped
• 1 garlic clove, minced
• 3 pounds potatoes (about 6 medium), cut into 1/2-inch cubes
• 1-1/2 cups fresh or frozen corn
• 5 cups chicken broth
• 1-1/2 teaspoons salt
• 3/4 teaspoon celery salt
• 3/4 teaspoon pepper
• 1/2 teaspoon dried thyme
• 1 pound cod or halibut fillets, cut into 3/4-inch pieces
• 1 cup heavy whipping cream