In a pan, heat up 2 tbsp of oil and temper mustard seeds, curry leaves and dried red chillies he mustrad seeds start to split and crackle.
Add in 4 fresh tomatoes blended to a smooth sauce and cook on high till the water is almost gone and it reduces. You can see that it really reduces in volume.
Then just add the potatoes and and eggplant with salt and red chilli pepper to taste. Add 1/2 cup of water and cook on medium heat for 10-12 minutes till it is all cooked.
And there you have it! Enjoy it hot with naan.