Wash and pat dry the brinjals and keep aside.
Take a mixie jar, add all the ingredients to grind.
Ground them on the pulse to form a paste. Do not add water.
Take the grounded powder into bowl and add 1tsp of oil and mix well.
Trim the brinjal stem and slit them in the middle without breaking them.
Stuff the masala mixture into all the brinjals.
Heat a pan with oil, add mustard, urad dal and cumin seeds, once they begin to crackle, add chopped onions along with curry leaves and fry till becomes translucent.
Add chopped tomatoes along with the remaining masala powder and cook on high to medium flame for 5 mints until tomatoes are cooked.