Red caviar, or salmon roe, adds a salty richness to this dish but this salad is fine without it.
Smoked salmon has slightly lower amounts of omega-3 fatty acids than fresh salmon but, like other oily fish, it provides a rich source of these essential nutrients.
Ideally, use freshly smoked salmon for the best result, but if you do use salmon that's vacuum-packed, make sure to check the use-by or best-before date.