Wash the potatoes and cook in plenty of boiling water for about 20 minutes. In the meantime, drain mandarins and gherkins separately and collect the juice. Clean and wash spring onions and cut into fine rings. Cut the mustard gherkins a little smaller. Cut the ham into wide strips. Drain potatoes, rinse and peel. Halve potatoes.
Mix Piccalilli and 100 ml mandarin juice, mix with warm potatoes, spring onions and ham. Let the salad stand for about 30 minutes. Roast mustard seeds in a pan without fat and take them out. Fold the cucumbers and mandarins into the salad and season with salt, pepper and possibly some mandarin juice or cucumber water. Put the salad in a bowl and sprinkle with mustard seeds. Serve garnished with parsley