Cut the potatoes in half and cook in a pressure cooker until they are soft. (Add salt to the pressure cooker when cooking) Remove skin, mash, and add the fresh turmeric, serrano peppers, garlic, lemon juice, garam masala, and salt to taste. Add cilantro if desired.
In a small pot, warm up the vegetable oil. Once heated, add in the mustard seeds and pieces of cinnamon.
When the mustard seeds stop crackling, pour that pot directly into the potatoes and mix everything well.
To make the batter for frying, mix together the graham flour, baking soda (or eno) and a little bit of water so it's a thick consistency.
Start making balls out of your potato mixture. You will be able to make about 12 medium size vada's.
When you are ready to fry, dip the potato balls into the batter to coat them, and then drop into your pot to fry. Let them turn golden brown, and then place them on a paper napkin to let off the excess oil.
To assemble, butter your pav and warm up on a pan. Once it's done, put about 1 tbsp of green chutney on both sides of the pav. Then put the vada in the middle, sprinkle on vada pav spicy masala if you have, and enjoy!