Begin by dicing the potatoes into small cubes and placing them in a bowl. Slice the red onion finely, grate the garlic and ginger, and chop the green chili and fresh coriander.

In a large pot, bring salted water to a boil and add the diced potatoes. Cook for about 10 minutes or until fork-tender. Once done, drain the potatoes and allow them to steam dry in the colander for a few minutes.

In a large skillet, heat a splash of vegetable oil over medium heat. Add cumin seeds and black mustard seeds, sautéing for about a minute until they start to pop. Add the sliced onions and cook for 15 minutes until they soften and turn golden. Mix in the grated garlic, ginger, and chopped green chili, cooking for an additional 2 minutes.

Add the cooked potatoes along with the frozen peas, ground spices, and lime pickle. Stir gently for about 5 minutes until heated through and well combined.

Unroll the puff pastry onto a floured surface and cut it into squares. Place a generous spoonful of the filling in the center of each square. Cut diagonal incisions on one edge, fold over, and seal the edges by pressing together. Brush with an egg wash.

Chill the assembled rolls in the fridge for 20 minutes. Preheat your oven to 190°C (375°F). Bake for 15-20 minutes or until golden brown and flaky.