Grind together the cumin, peppercorns and kashmiri chillies with the vinegar. Mix in the turmeric.
Heat oil and fry the onions till brown. Add prawns, ground masala, curry leaves, garlic, ginger and green chillies. Mix well and simmer for 10 minutes or until the prawns are cooked.
Note : Balcho can also be prepared using meat and fish.