#This is an extremely exotic sweet-and-sour dish which originally came from Persia.# Heat half the oil in a frying pan. Add the onions and turmeric, and cook gently until soft. Transfer to a pan, add the walnuts and stock, then season with salt and pepper. Stir, then bring to the boil and simmer the mixture, uncovered, for 20 minutes.
Cut the pomegranates in half and scoop out the seeds into a bowl. Reserve the seeds of one pomegranate. Transfer the remaining seeds to a blender or food processor, and process to break them up. Strain through a sieve, to extract the juice, and stir in the sugar and lemon juice.
Score the skin of the duck breasts in a lattice fashion with a sharp knife. Heat the remaining oil in a frying pan or char grill and place the duck breasts in it, skin side down.
Cook gently for 10 minutes, pouring off the fat from time to time, until the skin is dark golden and crisp. Turn them over and cook for a further 3-4 minutes. Transfer to a plate and leave to rest.
Deglaze the frying pan or char grill with the pomegranate juice mixture, stirring with a wooden spoon, then add the walnut and stock mixture and simmer for 15 minutes until the sauce has thickened slightly. Serve the duck breasts sliced, drizzled with a little sauce, and garnished with the reserved pomegranate seeds.
Serve the remaining sauce separately. #COOK'S TIP# Choose pomegranates with shiny, brightly colored skins. The juice stains, so take care when cutting them. Only the seeds are used in cooking the pith is discarded.