Vindaloo (original style)

Amazingly brilliant. I've not changed anything from this recipe:

75ml cider vinegar
700g pork shoulder, cut into 3cm chunks
4 tbsp ghee, neutral or coconut oil
500g onions, finely sliced (about 4 medium onions)
60g tamarind pulp
10 garlic cloves, finely sliced
5cm thick length of ginger, cut into slim matchsticks
4 ripe tomatoes, diced
2-4 small green chillies
10 curry leaves (optional)
1 tbsp jaggery or soft brown sugar
1 tsp salt
1 tsp black mustard seeds

For the masala
2 tbsp Kashmiri chilli powder or paprika
Seeds of 8 cardamom pods
1 tsp black peppercorns
8 cloves
1 tsp cumin seeds
½ tsp coriander seeds
½ tsp turmeric
5cm cinnamon stick

Grind masala ingredients, then add in the vinegar. Rub into the pork and leave to marinade for 3 to 4 hours. 

Heat the ghee in a large pot, then fry the onions over a medium-low heat until soft and golden. Meanwhile, soak tamarind pulp in 120ml of hot water for 15 minutes, then gently rub off pulp from seeds, then strain off the liquid and set aside, and discard the solids. 

Add garlic and ginger to the onions and stir in, cook for another 5 minutes, then add tomatoes, chillies and curry leaves and cook until tomatoes start to break down.

Add the pork and marinade, turn up heat to medium-high, mix in jaggery (sugar), salt and mustard seeds, and then add tamarind liquid. Bring to simmer, turn heat down, cover and cook for an hour. 

After an hour, remove the lid and thicken on a low heat for another 30 minutes. Serve with rice, naan or whatever.