Wash and clean the duck and cut it into medium pieces. Marinade the duck pieces with pepper powder and salt.
Heat oil in a pan ,and add Diced onions,ginger,garlic and green chillies and saute it well,till it is soft and transparent.
Add pepper powder,turmeric powder and garam masala powder and fry it for 2 minutes. Add the duck pieces to it and mix it well with the masala...let it stand on a medium flame for 5 minutes.
Now add Vinegar ,salt ,currly leaves,Cloves,and mace.mix it well. Take thin coconut milk and pour it to the pan ,mix it well,cover it with a lid..
Allow it to cook on a medium flame till the meat is tender. When the meat is cooked,add thick coconut milk ,mix it well and remove from fire.