Fennel washing, cleaning. Peel onion. Cut both into very fine strips. Orange wash hot, rub dry.
With a zest ripper cut the skin into thin strips. Peel the orange so that the white skin is completely removed. Remove the fillets between the parting skins. Squeeze the juice out of the parting skins
Wash parsley, shake dry, pluck leaves from the stalks and chop finely. Whisk parsley, orange zests, vinegar, mustard, honey, orange juice and oil. Season to taste with salt and pepper. Marinate the fennel, onion and orange fillets in the prepared marinade. Arrange on plates