Mix the fresh yeast with 3 tablespoons of flour and about 3 tablespoons of lukewarm milk. Cover the mixture and leave in a warm place until cracks start to form on the surface. Add the rest of the flour to a bowl, make a well in the middle, and pour the mixture you just made into the well. On the edges of the bowl with the flour, add the egg yolks, egg, sugar, salt, butter, and the rest of the milk. Now knead all the ingredients together until a smooth dough starts to form. Let the dough rise in a warm place until it has doubled in size, then refrigerate it overnight and knead it again the next day before continuing to work with it.
Preheat the oven to 375°F. Wash the salmon and pat it dry. Cube about 6 ounces of the salmon and freeze the pieces for 5 minutes.
Cut the rest of the salmon filet into two large pieces. Drizzle the lime juice over both pieces, season with salt and pepper, and roll them in the chopped herbs. Then freeze the salmon for 5 minutes.
Puree the cold salmon cubes with the chili powder, nutmeg, and heavy cream into a mousse, making sure to add the heavy cream gradually so that it can properly combine with the fish. The mousse should be smooth and shiny.
Roll out the brioche dough into a rectangle. Place one of the large pieces of salmon into the middle of the dough. Spread some of the salmon mousse on top of the filet and then carefully press the second piece of salmon onto it.
Wrap the salmon in the brioche dough.
Mix the egg yolk and lukewarm milk and brush the egg wash over the brioche dough. Now put the filled dough in a warm place for 45 minutes before scoring the dough with a knife and cooking it for 45 minutes at 375°F until golden brown.
