Heat oil in a pan. Once the oil is hot, add eggplant to the pan and cook for 10-12 minutes until the eggplant are slightly browned, stirring frequently.
Remove the fried baingan to a plate and keep it aside. Add mustard seeds, cumin seeds, asafoetida, fennel seeds, and carom seeds to the same oil and let them crackle for 3-4 seconds.
Add garlic and ginger and fry for 5-6 seconds.
Now add onions and fry until they turn slightly brown in color.
Add tomatoes and green chilies and fry for 2-3 minutes.
Add coriander powder, turmeric powder, red chili powder, and salt, and cook for a minute.
Then add methi leaves and cook for 3-4 minutes, stirring frequently.
Add the fried baingan slices and mix well. Check the eggplants, if they are still uncooked. If yes, then splash a little water, cover the pan with a lid and cook for 3-4 minutes.
Check for salt and add more if needed. Cook for another 2-3 minutes. Serve hot.