Preheat the oven to 180℃ and line a baking tray with baking paper.
Roll out the puff pastry dough gently to form a 9x13 inch rectangle. Cut the edges leaving an inch boarder on all four sides. And layer the strips on each edge to create taller sides.
Poke the dough with a fork all over the base and bake for 28-20 minutes or until golden and baked through.
Once baked remove from the oven and using a spoon press down the center of the puff to create a cavity in the center with the puffed and raised edges. Set aside.
To make the filling we need to boil the potatoes ahead of time, peel and crumble them into a plate, set aside.
In a pan add the oil, cumin seeds and let it sizzle. Add the ginger, green chilis and fry until you can smell their aroma in the air – about a minute.
Add the green peas and cook for 1-2 minutes on medium heat. Add the red chili powder, garam masala, cumin powder, chaat masala and fennel powder. You want to cook this on low to medium heat for 2 minutes until the spices are well incorporated.
Add the crumbled potatoes and salt, stir and cook for 2-3 minutes until well combined. Add fresh coriander, lime juice and take off the heat. Set aside to cool down little.
Assemble the tart with the potato filling and spread it evenly. Pipe over the chutneys, ketchup and yogurt. Season with a little chaat masala or you can also serve it with sev. Cut into squares and serve it with chai