Wash the zucchini and cut into thin slices. Peel the onion and cut into thin rings. Peel the orange like an apple, remove the white skin. Detach the fillets from the dividers with the knife.
Make a vinaigrette from oil, vinegar, orange juice, salt and pepper. Mix the zucchini slices, onion rings, orange fillets and salami slices with the vinaigrette and let stand for 15 minutes.