The pickled onions should be made at least 1 hour before serving the salad. Start by cutting the red onion into thin slices.
In a bowl whisk together the apple cider vinegar, honey and salt until well mixed. Then add in the sliced onion making sure that it is all fully submerged in the liquid. Allow to sit for minimum 1 hour until softened. Taste the onions approximately half way through pickling and add more honey if you prefer them to be sweeter.
Using a mandolin or a sharp knife finely slice the fennel bulbs into very thin slices. Wash the apple, cut in quarters and remove the core. Then also cut the apple into thin slices.
In a salad bowl combine the sliced fennels and apples, halved almonds and the pickled onions.
In a small bowl whisk together the ingredients for the dressing. Toss the salad with the dressing and sprinkle with fresh parsley before serving.