Prepare the filling so that the nuts are coarsely chopped, and the bread is slightly dried in a toaster and crumbled. Remove the zest from the lemon and squeeze out the juice. Finely chop the dill. Mix all the ingredients with soft butter.
Add salt, pepper and mustard to the fish. Put it on a baking sheet. Spread sprinkles on top of the fish. Mash it well with your hands.
We put it in a preheated oven to 160C °. Bake for 15 minutes.
Serve immediately.