Add the oil to your pan and once hot, add the mustard seeds and split bengal gram.
Once the mustard seeds pop, add your onions, ginger, green chilli and sauté till the edges of the onions turn brown.
Roughly tear up/ chop the curry leaves and add it to the pan.
Add the tomatoes and sauté for 1 minute.
Add salt, turmeric and hing to the tomatoes and sauté for another minute.
Mix the gram flour with 4 tbsp water and ensure the mixture is as smooth as possible.
Add half a cup of water to the vegetables and bring to a gentle boil.
Strain the gram flour mixture into the pan while mixing constantly.*
Add an additional cup of water until it's at your desired consistency.
Taste and adjust the seasoning.
Let it boil for 20 seconds before turning it off.