In a large baking tray, place the onion with its peels, greased eggplant, and tomatoes and roast the veggies for 30 minutes at 200 degrees preheated oven. Set it aside to cool down completely or you can do it directly on the stovetop by placing a wire rack.
Skin the eggplant and mash it completely using a fork. Peel the onions and roughly chop or process them in a food processor. Separate the skin and seeds from the tomatoes and mash them roughly.
In a hot wide pan, add oil, ginger, garlic, green chilies, and hing and stir it around for a minute or two.
Add the onions, tomatoes, turmeric, coriander powder, chili powder, and some salt, mix well and cook for a
couple of minutes until you see it starting to dry out.
Now add the achaari masala, National Crushed Mixed Pickle, and mashed baingan and combine it well with the tomato mixture and cook until you see the bharta coming together.
Adjust the seasoning and garnish it with some fresh coriander or mint.
Enjoy Achari Baingan Bharta with Phulkas.