2 lbs (1 kg) green (unripened) mangoes
3 tbsp (45 mL) salt
1¾ cups (425 mL) granulated sugar
1 large head garlic, cloves peeled and lightly smashed
1 tbsp (15 mL) cayenne pepper
1 tsp (5 mL) ginger powder
1 tsp (5 mL) nigella seeds (kalaunji)
1 tsp (5 mL) cumin seeds
½ tsp (2 mL) black peppercorns
½ cup (125 mL) cider vinegar, divided