Fry duck:

• Place duck in a large frying pan. Add turmeric powder, chili powder and crushed black pepper. Season with salt. Coat duck pieces in the spices. Marinate in the refrigerator for about 30 minutes or until duck is cooked through and water dries.
• (Alternatively, transfer the mixture to a pressure cooker and cook for about 4-5 whistles)
• Meanwhile, heat oil for deep frying over medium-high heat. Fry duck in batches until browned. Drain on an absorbent paper towel. Set aside.
• To the same pan, add mustard seeds and allow to splutter. Add 2 sprigs of curry leaves. Add garlic, ginger and green chilies. Sauté, stirring constantly, for 1 minute or until fragrant.
• Add shallots and onions. Sauté, stirring occasionally, for 3-4 minutes or until browned. Add ground turmeric, coriander powder, crushed black peppercorns, garam masala and red chili powder. Sauté, stirring constantly, for one minute.
• Add fried duck pieces. Stir. Add 1 cup water. Cook, covered, for 3 minutes or until the sauce gets really thick and coats the duck pieces. Add vinegar and 1 sprig of curry leaves. Stir fry for 4-5 minutes.
• Garnish with more curry leaves if you like.