Heat the grill. Split and lightly toast the croissants. Meanwhile, make the scrambled eggs. Melt the butter in a frying pan. Beat and season the eggs and scramble lightly in the pan. When the eggs are just cooked, but still soft, stir in the double cream and chopped chives.
Fill each croissant with a few slices of smoked salmon and the creamy scrambled egg. Sprinkle with some black pepper and extra chopped chives.