For the fennel salad with oranges and carrots, peel 2/3 of the oranges and squeeze the rest. Fillet the peeled oranges. Remove the green from the fennel bulb and set aside. Cut off 1 cm from the bottom of the fennel bulb.
Cut the rest into very thin slices. The best way to do this is with a vegetable slicer. Clean the carrots and cut into julienne strips. Mix the orange juice with mustard and olive oil.
If necessary, season with salt and pepper. Add the carrot julienne, fennel slices and orange fillets to the vinaigrette and mix well.
Let the salad marinate for 1-2 hours. Add the spring onions just before serving.