Goan chicken vindaloo

Method
Prep:30min  ›  Cook:1hr  ›  Extra time:1hr marinating  ›  Ready in:2hr30min 

1. Cut a few shallow slits into each chicken drumstick and place into a resealable plastic bag; set aside. Heat 5 tablespoons of vegetable oil in a large pot over medium-high heat. Stir in the onion, garlic and ginger. Cook and stir until the onion has turned golden brown, about 7 minutes. Remove the pot from the heat, and use a slotted spoon to scoop the onion mixture into a blender. Leave as much oil in the pot as you can, and set aside for frying the spices later. Add 3 tablespoons white vinegar, coriander, cumin, garam masala, black pepper, salt, turmeric and cayenne pepper. Puree until smooth, then pour into the bag with the chicken; mix until the chicken is evenly coated and squeeze out excess air. Marinate at room temperature for 1 hour, or in the fridge for 3 hours or longer.
2. After the chicken has marinated, heat the oil left in the pot over high heat; stir in the curry leaves and mustard seeds. Once the mustard seeds have finished popping and have turned grey, remove the chicken from its marinade, and cook until browned on all sides, about 5 minutes. Pour in the remaining marinade and water. Bring to a simmer, then reduce heat to medium-low, cover and simmer 20 minutes.
3. Heat oil in a deep-fryer or large saucepan to 190 degrees C.
4. While the chicken is cooking, deep fry the potato cubes until golden brown. Drain on kitchen paper. Once the chicken has cooked for 20 minutes, stir in the potatoes and 2 tablespoons of white vinegar. Cover and continue to simmer until the chicken is no longer pink at the bone, at least more 10 minutes.