Boil or steam the potatoes and mash it. It should be around 1 cup of mashed potatoes.
Finely chop mushrooms, walnuts and coriander leaves.
Take a mixing bowl and add mashed potatoes, puffed amaranth seeds, chopped mushrooms, chopped coriander leaves, walnuts, ginger garlic paste, salt, and spice powders.
Mix everything well and form a dough out of these. Mushrooms will release some water and that will be taken up by walnuts and puffed amaranth. If you couldn't able to make a dough, add more puffed amaranth.
Make small orange-sized balls out of the dough and shape them into patties.
Take a tawa and fry these on a medium flame using little oil on both the sides.