Proper British Fish Cakes

I've been streaming a lot of British cooking shows lately, which is what inspired this. Not only do these look and taste amazing, they are also very inexpensive to make. Serve with watercress and lemon wedges.

Ingredients

• 0.5 cup mayonnaise
• 2 tablespoons capers, drained and chopped
• 1 tablespoon finely chopped shallot
• 1 tablespoon finely chopped Italian parsley
• 1 tablespoon finely chopped fresh tarragon
• 2 teaspoons prepared horseradish
• 1 teaspoon Dijon mustard
• 1 pinch cayenne pepper
• 0.5 cup milk
• 1 bay leaf
• 1 pound cod, cut into 1-inch pieces
• salt and freshly ground black pepper to taste
• 12 ounces russet potato, peeled and quartered
• 1 pinch cayenne pepper
• 1 tablespoon finely chopped Italian parsley
• 1 tablespoon sliced fresh chives
• 1 teaspoon finely grated lemon zest
• 0.3333333333333333 cup all-purpose flour
• 1 large egg, beaten
• 1 cup panko bread crumbs, or as needed
• 0.25 cup vegetable oil, or as needed

Steps

1. Mix mayonnaise, capers, shallot, parsley, tarragon, horseradish, mustard, and cayenne together in a bowl for tartar sauce and refrigerate until needed.
2. Add milk and bay leaf to a saucepan and place the pieces of fish over the top. Season with salt. Bring to a simmer over medium heat, and cook for about 1 minute, stirring occasionally. As soon as the fish firms up, but before it starts to flake apart, turn off the heat and cover. Let sit for 5 minutes before draining. Let cool, about 10 minutes. Refrigerate until needed.
3. Meanwhile, bring a pot of lightly salted water to a boil. Add russet potato and boil until tender but not falling apart.
4. Drain and mash potato in a bowl. Season with salt, black pepper, and cayenne. Add parsley, chives, and lemon zest; add 1 tablespoon tartar sauce mixture. Mix until combined. Flake chilled fish over the top. Mix until combined.
5. Scoop out ¼ of the mixture and form into a patty. Repeat with remaining mixture.
6. Dust cakes with flour on both sides. Brush both sides of cakes with beaten egg. Coat in bread crumbs.
7. Heat oil in a skillet over medium heat. Pan-fry patties in the hot oil until golden brown and heated through, 3 to 4 minutes per side. Drain on paper towels before serving with tartar sauce.