In a mortar and pestle, crush ginger, garlic, and green chillies.
Heat 1 tsp oil in a pan. For a few seconds, sauté the paste of ginger, garlic, and green chillies until the raw aroma of ginger and garlic is gone.
Add chopped onions and sauté till the onions turn translucent.
Add the spices - cumin powder, garam masala powder, red chilli powder, coriander powder and turmeric to the mix and stir well.
Switch off the gas and add chopped coriander leaves.
Add the sautéd mixture to mashed vegetables. Also, add breadcrumbs and salt and mix well.
Make the vegetable patties the same size as that of the burger buns. Keep these patties aside.