Wash and keep aside baingan so that they turn dry. Cutting their stem is your personal choice. However we don't cut it.
Take a small bowl and add all the spices mentioned, which includes red chilli powder, turmeric powder, coriander powder, cumin powder, Garam masala, Mango powder, salt and give them a good mix. Keep aside.
Now take a baingan & from the lower side (extreme opposite to stem side), cut 2 marks across the baingan dividing it in 4 parts. MOST IMPORTANT point is that don't cut in a way that 4 parts get separated. Baingan should remain intact from the stem side. Cut all the baingans likewise.
Using your fingers tips, fill the spices mix in each baingan one by one. You can also use spoon if you like.
Now add oil in a wide pan and place on flame. We are using mustard oil but you can take any oil you usually use for everyday cooking.
When the oil gets cooked, as it was mustard one, add all the brinjals one by one in the pan.
Cover the pan with a lid. Let them cook on low flame for 4 to 5 minutes.
Remove the lid and turn their side.
Likewise keep on cooking it with the lid on, then turning their side after short intervals, again lid on & so on. They need to be checked quite often & turning their side so that baingans must not burn.
When the baingans turn soft & mushy, they are done. It may take from 18 to 20 minutes.
Enjoy warm with chapati or the way you want.