firstly, in large kadai heat 2 tbsp oil. add ¼ tsp methi, 1 tsp mustard, ½ tsp cumin and pinch hing. splutter tempering.
now add 10 small onions, 10 cloves garlic and saute on medium flame.
further, add 1½ cup tomato puree and mix well combining everything well.
add ½ tsp turmeric, 1 tsp chilli powder, 2 tsp masala powder, 1 tsp salt and 1 tsp jaggery. mix well.
also add ½ cup tamarind extract, 1 cup water and a few curry leaves.
cover and boil for 10 minutes or until everything is cooked well and oil separates.
add 2 tbsp coriander and mix well making sure the flavours are balanced.
finally, enjoy vengaya kulambu or spicy onion curry with rice, dosa or idli.