In a small bowl, combine the butter and orange zest. Brush the slices of bread with this mixture. Place them on a baking sheet and toast in the oven for about 10 minutes, or until golden brown. Set aside.
In the bowl of a food processor, combine the cheese, 150 g salmon, cilantro, paprika and lemon juice. Mix everything for 2 minutes or until a smooth cream is obtained. Pour onto plastic wrap, roll into a log shape and refrigerate for 2 hours.
Remove film and cut log into 20 slices. Place a ring on each crouton, garnish with a strip of smoked salmon and a little chives.