Dip them in water until needed or else the aubergine/eggplant will turn black.
In a heavy bottom pan add oil.
1 teaspoon oil
Once hot, add cumin seeds and asafoetida.
1 teaspoon cumin seeds, ¼ teaspoon asafoetida
Once the cumin seeds splutter, add the turmeric powder, red chili powder, and coriander powder, and saute for a few minutes. Be careful not to burn the masala.
½ teaspoon Turmeric powder, 1 teaspoon Red chili powder, 2 tablespoon coriander powder
Add in the cut aubergine/eggplant, and potatoes and salt.
Salt
Mix everything, cover, and cook on a medium stove stirring in between.
After 7-8 minutes check if the potatoes are done.
Once the potatoes are done add garam masala and amchoor powder and mix
1 teaspoon Garam Masala, 1 teaspooon Raw mango/Amchoor Powder
The bhaji is done when the potatoes are pierced easily with a knife or a fork or the back of your spoon.
Notes
Masala measurements are a rough guide, use as required.