Preheat the oven to 170°C.
Heat a drop of oil in non-stick frying pan. Place the duck fillets in the pan, skin-side facing downwards, and fry for about 8 minutes until the skin is golden and crispy. Turn them over and cook for 2 more minutes to seal the meat.
Meanwhile, mix the remaining ingredients into a paste. Use the Teriyaki if you don’t have any Mirin.
Remove the duck breasts from the pan and place them in a baking dish. Brush them with the glaze – both the skin and the meat, then pour over the remaining mixture.
Cook them in the oven for about 8–10 minutes, until golden, then rest them for 5 minutest, before carving them into slices.
Serve with noodles or rice, with the jus poured over the dish.