Season the salmon with salt and pepper. Then spread the top of the salmon with dijon mustard. Sprinkle with pistachio nuts and panko evenly coating it very well.
Heat a saute pan on medium heat. Once hot, add the oil. Place the salmon crusted side down into the pan. Cook until golden brown then flip the salmon over. Transfer the pan to the oven.
Bake for 8-10 minutes, to an internal temperature of 125°F using a thermometer. (Baking time will vary based on your fish fillet thickness.)
In a bowl, whisk together the ingredients for the horseradish cream. Season with salt and pepper to taste.
Drizzle the salmon with horseradish cream and serve with bread.