1. Heat the fennel seeds for one minute, dry, in a non-stick pan. Let cool, and lightly crush with a rolling pin or in a mortar.
2. Peel and slice the onions into very thin strips.
3. Peel the oranges, over a large plate. Cut into thin slices and remove seeds.
4. In the plate, arrange the orange slices. Overlay with onion rings and sprinkle with fennel seeds. Season with salt and pepper.
5. Drizzle with olive oil and apple cider vinegar. Arrange the pitted black olives. Cover, and refrigerate for at least one hour before serving. Serve with grilled meats or roasted chicken.