Grate the orange zest and squeeze the juice. Mix with all the other ingredients in a jar.
Place the thighs in plastic freezer bags and pour over them the mixture. Tie the bag, shake it to make sure all are well covered with the marinade.
Chill for a minimum of two hours, preferably overnight in the refrigerator. Occasionally shake the bag and massage the meat through the bag.
Take the meat out of the fridge about an hour before cooking.
Preheat the oven to 180°C.
Place the thighs in a roasting tin, season with salt and pepper, then pour the marinade on top. Cook for 30-35minutes.
For the final 5-10 minutes put the thighs on the barbecue and cook until lightly charred.