Yankee Fish Cakes

Ingredients

• 9 tablespoons unsalted butter
• 1 medium yellow onion (roughly chopped)
• 1 celery rib (roughly chopped)
• 1 lb haddock (boneless and skinned, or cod, cut into 4 large pieces)
• 1/3 cup heavy cream
• 1 1/2 cups dried breadcrumbs
• 3 tablespoons mayonnaise
• 2 tablespoons minced fresh dill
• 1 tablespoon Dijon mustard
• 1 tablespoon fresh lemon juice
• 1 tablespoon minced dill pickle
• 1 teaspoon lemon zest
• 1/2 teaspoon Tabasco sauce
• 1 egg
• kosher salt, to taste
• fresh ground black pepper, to taste
• 1/2 cup yellow cornmeal