Put the bagels, cut side down, on a sandwich grill. Without closing the lid, leave them to toast for 2–3 minutes until golden. Remove from the grill.
Spread the bases with the cream cheese and then top with the gravlax. Scatter the chopped chives over the bagel and season with black pepper.
Top with the bagel lids and return to the sandwich grill. Lower the top plate and toast for 2–3 minutes or according to the manufacturer's instructions until golden and crispy. Serve immediately with a sprinkling of black pepper.