In a large mixing bowl, combine leftover matar or aloo poha, mashed potatoes, garam masala powder, chaat masala powder, hing, turmeric powder and salt to taste to form a soft dough.
Place in airtight container and chill in refrigerator for about 10 to 15 minutes or until you want to fry them.
You can fry them right away too, but chilling them a bit helps in maintaining the structure of the cutlet and prevents them from breaking apart.