To prepare the chutney, heat oil in a pan over medium heat and saute onion, garlic until they turn light brown in color.
Then add chopped tomato, salt, turmeric powder and chili powder. Fry the masala till tomato are soft and oil get separated from the masala. Turn off the heat and let masala cool down to room temperature.
Blend the masala in mixer (buy it here) to smooth puree and transfer to a bowl.
For tempering the chutney, heat ghee in a pan over medium heat.
Add mustard seeds once they start making crackling noise add curry leaves and dry red chili. Fry for 1 – 2 minutes and then pour the tempering over the chutney.