Preheat the oven to 200C/400F/Gas 6.
Place the oil into an ovenproof dish and place into the oven for five minutes, or until very hot. Add the potato pieces and season well with salt and freshly ground black pepper. Place into the oven and roast for 30 minutes, or until crisp and golden.
Remove from the oven, add the soy sauce and sesame seeds and stir to combine.
For the dressing, place all of the dressing ingredients into a bowl and stir well to combine.
To serve, place the mint, Baby Gem lettuce leaves and chard in a large clean bowl. Add the dressing and mix well to coat the leaves, then add the potatoes. Arrange the salad onto four plates and top with smoked duck breast slices.
