Method:
1 Pour chicken stock into a saucepan over medium heat, add butter and potatoes, bring to a simmer, simmer for 10-15 minutes or until the potatoes are tender, the liquid has been absorbed and the potatoes or frying the butter and are crispy and golden.
2 Heat a frying pan over low heat, season the duck breast with salt and pepper and cook skin-side down for 8-10 minutes, turn the breast over and increase heat to high, cook for a further 3 minutes. Rest for 5 minutes and then slice. Tip excess fat from pan, place pan over medium heat.
3 Deglaze the pan with the orange juice, add the stock, sugar and vinegar and simmer for 2-3 minutes to reduce. Whisk in the chilled butter a little at a time to create a thickened glossy sauce, season with salt and pepper.
4 Arrange the duck slices on a plate with the orange segments and potatoes to the side, pour over the sauce to serve.