In a small bowl, mix together mayonnaise, Dijon mustard, chopped capers, lemon juice, Worcestershire sauce, and hot sauce if desired. Stir well until smooth, and set aside for at least 15 minutes.

Preheat your oven to 375°F (190°C). Place the salmon fillet on a lined baking sheet, drizzling it lightly with neutral oil and seasoning with kosher salt and pepper. Bake for 15-20 minutes, or until the salmon flakes easily. Let it cool and then flake it into a mixing bowl.

In a skillet, melt butter over medium-low heat. Add chopped shallots and cook for about 3 minutes until translucent. Add garlic and sauté for another minute until fragrant.

In the bowl with flaked salmon, add mashed potatoes, breadcrumbs, sautéed shallots, Old Bay seasoning, and Dijon mustard. Mix gently until well combined, keeping some texture.

Take about 3 tablespoons of the salmon mixture and shape into oval patties. Arrange on a plate.

In a skillet, heat neutral oil to 375°F (190°C). Fry croquettes for 2-3 minutes per side until golden brown, about 6-8 minutes total. Transfer to a paper towel-lined plate and sprinkle with salt.

Plate the croquettes while hot, garnishing with fresh parsley. Serve with remoulade sauce on the side.