Slice the beetroot into very thin strips using a vegetable peeler or knife.
Mix the orange juice, lemon juice, olive oil, mustard, salt and pepper to create a marinade. Thoroughly coat the beetroot slices in the marinade and refrigerate for 20 mins.
Cut the onion into 2 mm slices for the garnish, halve the pecan nuts. Dissolve the sugar in a pan with a little water and heat through. Caramelize the onions and pecan nut halves in the pan, deglaze with the soy sauce. Serve the beetroot slices together with the marinade, garnish with the onion & nut mixture, sprinkle with parsley.