Combine olive oil, rosemary, minced garlic, soy sauce, 2 tbsp sugar, salt and pepper and the juice of one orange. Mix well.
Marinate chicken pieces in the mixture for half a day or overnight.
Roast chicken in an oven at 220ºC for 20 minutes. Then reduce temperature to 190ºC and continue roasting for 15 - 20 more minutes or until chicken is brown.
Baste chicken with leftover marinade from time to time.
Add orange slices and continue baking for 5 minutes until the fruit caramelizes.
Serve with brown rice.