In a large bowl, mix together hake, 1/4 cup bread crumbs, 1/4 cup parsley, mayonnaise, coriander, shallots, mustard, tuna and egg. Season with salt and pepper. Sprinkle remaining bread crumbs on a baking sheet.
Form mixture into patties roughly 1 1/2 inches thick and 2 inches in diameter, using about 1/4 cup of the mixture per patty. Coat each fishcake with the bread crumbs and set aside.
Heat a large skillet over medium-high heat with enough vegetable oil to coat the bottom and cook the fishcakes until browned on both sides, about 3 minutes per side, in batches as needed.
Garnish with Dijon Caper Mayonnaise and chopped parsley.
Dijon Caper Mayonnaise:
In a medium bowl, mix all the ingredients together until smooth. Refrigerate until ready to use.