Place mint leaves in a pitcher. Use a wooden spoon to bruise leaves. Add pomegranate juice and simple syrup; stir to dissolve. Cover and chill 2 to 4 hours. For each serving, fill a glass with ice.
Preheat the oven to 180°C. Rub the duck fillets with sea salt and arrange in an ovenproof casserole. Add the pomegranate syrup, chicken stock, the juice of 1 orange and a piece each of orange and ...