Make a dressing by mixing the Greek yoghurt, mayonnaise, mustard, dill, chives, lemon juice, smoked paprika, chilli flakes and salt and pepper to taste in a bowl.
Drain the salmon. Add the salmon, gherkins and shallots to the dressing and mix gently until everything is well combined.
Top your breadrolls with some lettuce and then spoon the salmon salad on top. Enjoy!