For the spinach-salmon strudel, sauté finely chopped onion in olive oil. Add blanched spinach and steam briefly, then let cool.
Mix in the cream cheese with semolina and yolk. Add finely chopped salmon and spices. Spread the resulting mixture on the two rolled out pieces of puff pastry and form the two strudels by rolling them up.
Brush the spinach-salmon strudel with egg white and bake in the oven at 220°C for about 30 minutes.