Cut the boiled potatoes into bite-sized pieces, and break the cauliflower into small florets.
Mix the ingredients for the vinaigrette, and season to taste with salt and freshly ground pepper.
Put the potatoes, cauliflower, apple, spring onions, parsley, salted almonds and feta in a large bowl, pour over the vinaigrette and toss everything together well.
If you like, top with a sprinkling of fresh herbs and a little freshly ground pepper before serving.