Half-fill the base of a steamer with water, bring to the boil then add the potatoes to the water. Season the salmon and arrange in a single layer in the top of the steamer. Cover and cook the potatoes for 12–14 minutes until just tender, and the salmon for 8–10 minutes until cooked through.
Make the dressing by forking the oil, lemon rind and juice, honey and seasoning together in the base of a salad bowl. Add the onion, capers, brine and the anchovies. Drain the potatoes and toss with the dressing while still hot. Skin and flake the salmon, discarding any bones, and arrange on top of the potatoes. Leave to cool, cover and chill until required.
When ready to serve, tear the parsley over the fish and gently toss the salad together. Serve in shallow bowls.