Boil the potato, peel the skin and mash it, but not like a paste. Take the pastry puff sheet and cut into 9 small squares.
In a kadai, put a little oil and add the cumin seeds. When they splutter add the fennel seeds. Fry for about 30 seconds and add the smashed potato. Add garam masala, turmeric and salt. Mix everything well and keep on flame for about a minute. Remove from gas and allow it to cool a little bit, say for about 5 minutes.
Now take the square piece of the pastry puff sheet and put some of the potato mixture in the centre.
Dip your finger in water and apply water on all the four sides of the sheet so that the sides can be stuck.
Now fold the square piece diagonally, in the shape of a triangle. Make the remaining squares pieces in the similar way.
Preheat the oven to 400 degrees F.
Place the made pastries in a baking tray and bake it for approximately 20 minutes or until the puffs are golden in color. Once they turn slightly golden then turn it over and allow the other side to cook too.