In a small frying pan on medium low heat, add coriander seeds, cumin seeds, black peppercorns and fennel seeds. Roast them for a minute stirring them constantly until aromatic. Take it out in a bowl. And let it cool down.
Now using a spice grinder, grind the roasted whole spices coarsely to make a spice mix.
Now place a frying pan on medium flame. Add Oil. Add the prepared spice mix along with asafetida (hing) and cook it for 20 seconds.
Next, add in the finely chopped ginger and green chilies. Sauté them for 30 seconds.
Now add the finely chopped onions, along with red chili powder, Dry Mango Powder (Amchur), and Salt.
Mix it well, and cook until onions soften.
Now add besan and finely chopped cilantro. Cook for another minute, and turn off the flame.