Take your cream cheese out of the fridge 30 minutes before assembling so it's easy to spread.
Toast your bagels until lightly golden and crisp. Set aside.
Spoon the cream cheese onto a large board or serving surface. Use the back of a spoon or offset spatula to spread it in a thick, swooping layer with beautiful peaks.
Arrange chunks of smoked salmon directly on and around the cream cheese.
Scatter thinly sliced red onion and capers over the top. Finish with a pinch of flaky sea salt.
Arrange sliced cucumber around the edges of the board.
Tuck toasted bagel halves all around the board and serve immediately. Let everyone build their own!