Salt and pepper the beef fillets, fry them on both sides in rapeseed oil for about 2 minutes. Remove from pan and wrap in aluminum foil. Mix the orange juice with the mustard and honey.
Peel the onion and cut into rings, wash the apples and cut into small pieces. Toast together in the roast with the marjoram for 1 - 2 minutes, then season with salt and pepper.
Halve the rolls, brush all halves with quark and sprinkle with herbal salt. Cut the beef fillet into 1 cm thick strips and place the apples, onions and rocket on the halves of the bread roll. Sprinkle some orange dressing on top, drizzle with gravy and serve.