2 tablespoons tamarind paste (see Recipe Note)
1 tablespoon white vinegar
Before prepping the ingredients, turn the slow cooker on to the HIGH setting for 15 minutes, until the insert is warmed through. Julienne 1 inch of the ginger and set aside for garnish. Mince the remaining ginger.
Heat the oil in a large skillet over high heat, with a lid handy. Tilt the skillet to pool the oil and add the fenugreek seeds; cover immediately to prevent splattering. When the seeds have stopped sputtering, add the onions. Sauté the onions for 7 to 8 minutes until light golden-brown. Add the browned onions to the slow cooker and mix in the pork, minced ginger, garlic, serrano chiles, turmeric, ground red chile, and salt. Cook on low heat for 3 1/2 hours.
Grind together the coriander seeds, cumin seeds, mustard seeds, cloves, cardamom, peppercorns, cassia, and sugar in a spice grinder. Add the ground spice blend to the pork, mix well, and continue to cook on low for an additional 30 minutes. Turn the slow cooker off and stir in the tamarind pulp and vinegar. Serve garnished with the julienned ginger.
Reprinted with permission from The New Indian Slow Cooker by Neela Paniz, copyright (c) 2014. Published by Ten Speed Press.