To make the puri, mix together wheat flour, salt, sugar, gram flour, semolina, hot oil, water and mix. Knead the dough and keep aside.
In the mean while, add in oil, mustard seeds, cumin seeds, green chillies, hing, turmeric and potatoes in a pan.
Add salt and water and mix well. Let it cook for a while.
Roll out the dough and fry it to make the puris.
Serve the puri and bhaji together.