Remove the skin, any bones and fatty pieces and the grey flesh between the pink and the skin from the salmon. Finely slice and then finely dice the salmon.
Finely dice the shallot and cut the chives in small slices.
Roughly chop the capers and add them, along with the chives, mustard, onion, lemon and a little salt and pepper to the salmon. Mix all together well. The mixture is best chilled at this point for around 20-30 minutes, so cover and put in the fridge. You can, however, also serve straight away.
When ready to serve, use a plating mould or just a medium-large cookie/scone cutter or crumpet ring and press into the mould. Carefully remove the mould so it stands in a short cylinder. You could also fill a small, shallow bowl/dish then turn it over on to a plate. Serve immediately, garnished with chives.
Video
Notes
Shallot is generally the best option here but you can also use red onion and sweet onion also works.