In a small bowl whisk tamarind with water.

Heat a heavy skillet over medium heat.

Add cumin, mustard and coriander seeds; toast, stirring, until they begin to pop.

Transfer the above mix to a coffee or spice grinder along with curry leaves, cinnamon and peppercorns.

Process to a fine powder and add to tamarind.

In a blender, combine garlic, chillies and ginger and make it like paste.

Add 2 tablespoons of mustard oil and spiced tamarind mixture and saute until combined.

In a large bowl place pork and pour blender contents over and toss to combine.

Marinate covered 2 hours at room temperature or refrigerate overnight.

In a large skillet heat remaining 1/2 cup mustard oil over medium-high heat.

Add onion and sautee for 10 minutes, or until lightly browned.

Add turmeric, fenugreek, chilli powder to taste, coriander and salt; cook, stirring constantly, 30 seconds until spices are fragrant.

Reduce heat to medium and add pork and Cook often 5 minutes.

Stir in vinegar and water.

Reduce heat to low, cover and cook, about 1 1/2 hours, or until pork is very tender.

Garnish with browned onions and cilantro.