For the crust, beat the butter until creamy. Grind the smoked salmon in a hand mixer and stir into the butter. Season with horseradish, salt, cayenne pepper and juice of one lemon and stir in the grated white bread. Preheat oven to 240 degrees.
Season salmon fillets lightly with salt and brush about 1 cm thick. Heat a little oil in a gratin dish and pour in the salmon slices with the crust facing up.
Bake in the oven heated to 240 °C for 8 minutes until golden brown. Turn off the heat and cook the salmon for a few more minutes with the door slightly open.
Heat the butter sauce, season with finely chopped dill and a small amount of lemon juice and serve with the salmon fillets.
Tip: A beetroot-leaf salad dressed with salad dressing tastes exceptionally good with it.