Clean the red cabbage, quarter it and cut out the stalk. Cut cabbage into fine strips and knead with 1/2 teaspoon salt. Wash chicken fillets, dab dry and season with salt and pepper.
Heat 1 tablespoon of oil in a frying pan. Fry the chicken fillets in it at medium heat for 10-12 minutes. Turn from time to time. Peel 2 oranges so that the white skin is completely removed. Remove the fillets from the parting skins.
Peel and wash the carrot and cut it into fine sticks. Clean, wash and cut the leek into thin rings. Chop the walnuts a little smaller. Squeeze the rest of the orange. Mix orange juice, vinegar, pepper and sugar.
Fold in 2 tablespoons of oil. Add the marinade to the red cabbage. Fold in orange filets, carrot sticks, leek and walnuts. Season to taste again. Cut the chicken fillets into slices and arrange on plates with the red cabbage salad.