Duck vindaloo

Ingredients

• 1.8 kilograms whole duck
• 1/4 cup (35g) plain (all-purpose) flour
• 1 tablespoon peanut oil
• 2 teaspoons cumin seeds
• 2 teaspoons fenugreek seeds
• 1 teaspoon ground coriander
• 1 teaspoon ground turmeric
• 1/2 teaspoon ground cardamom
• 4 fresh small red thai chillies, chopped coarsely
• 3 cloves garlic, quartered
• 2 1/2 centimetre piece fresh ginger (15g), sliced thinly
• 1/3 cup (80ml) white vinegar
• 1/2 cup (125ml) chicken stock
• 1 red onion (170g), chopped finely
• 4 potatoes (800g), chopped coarsely
• 2 tablespoons chicken gravy powder
• 2 tablespoons water
• 1/2 cup loosely packed fresh coriander leaves