Soak the kidney beans overnight and later clean it and allow to boil in a pressure cooker with little salt for at least 5 to 6 whistles or till it becomes tender and little mushy in texture.
Drain the water and allow to cool. In the mean while, peel the potatoes and boil them.
When both kidney beans and potatoes are cooled down, take them in a plate and mash them together.
Next add chopped onions, coriander leaves, and green chillies into the mashed mixture.
After that add all the spices including salt, dry ginger powder, red chilli powder,roasted cumin powder, chaat masala and mix them well.
Next add the all purpose flower for binding and make a dough.
Apply oil on your palm and take lemon size balls and flatten them using your palm.
Heat a skillet and brush it with oil and fry the kidney bean patties under slow flame until both the sides are golden brown.
Serve them hot with ketchup or your favorite dip.