Place pork, onions, tomatoes, ginger, garlic, ground turmeric, ground coriander, garam masala, ground black pepper, red chili powder, green chilies, a sprig of curry leaves, white vinegar (if using), and salt in a pressure cooker over high heat. Cook until the sixth or seventh whistle.

When the steam has escaped, open the lid, and place the cooker over medium-high heat. Simmer until all the water dries up. Set aside.

Meanwhile, heat oil in a large pan over medium-high heat. Splutter mustard seeds. Fry fennel seeds, cardamom pods, cloves and bay leaves until aromatic. Add shallots, dried red chilies and a sprig of curry leaves. Saute, stirring, until the shallots are browned.

Stir in cooked pork. Sauté, stirring occasionally, for 4-5 minutes. To serve, garnish with coriander leaves.

Serve Kerala pork fry with rice or any flatbread.