Sri Lankan–Style Black Pork Curry

Name: Sri Lankan–Style Black Pork Curry
Ingredients: 15 fresh curry leaves; 18 whole cloves; 5 cardamom pods; 1 4-long Ceylon cinnamon stick, broken into small pieces; 2 Tbsp. black peppercorns; 1 Tbsp. coriander seeds; 1 tsp. cumin seeds; 1 tsp. fennel seeds; 1½ lb. skinless, boneless pork shoulder (Boston butt), cut into 1 pieces; ½ cup distilled white vinegar; 1 tsp. turmeric powder; 1 Tbsp. Diamond Crystal or 1¾ tsp. Morton kosher salt, plus more; ¼ cup vegetable oil; 2 medium onions, finely chopped; 6 garlic cloves, finely grated; 1 2 piece ginger, peeled, finely grated; 10 fresh curry leaves; 1 lemongrass stalk, bottom third only, tough outer layers removed, lightly bruised; Steamed rice (for serving); A spice mill or a mortar and pestle