Preheat oven to 220°C/ 425°F/ Gas Mark 7.
Slash the skin of the duck breasts then season generously with salt and pepper and place in a hot, dry frying pan over a high heat - skin side down. Cook for 2 minutes then turn and cook for 2 minutes again.
Meanwhile, in a small roasting tin, mix the marmalade with the soy sauce and sesame seeds. Add the duck and coat well.
Roast in the preheated oven for 10 minutes then rest for 10 minutes before slicing.
Drizzle the juices from the roasting tin over the meat and serve with potatoes and seasonal vegetables.
