Begin by preparing your vegetables for the filling of the Spiced Pea and Potato Rolls. Dice the potatoes into small cubes, then set aside. Next, slice the red onions finely, grate the garlic and ginger, and finely dice the green chili. Finally, chop the fresh coriander and keep everything organized for easy access during cooking.

In a medium saucepan, bring salted water to a boil. Add the diced potatoes and cook them for about 10 minutes or until they are fork-tender. Once cooked, drain the potatoes and allow them to cool slightly, ensuring they retain their shape and texture for the filling of your rolls.

Heat a couple of tablespoons of vegetable oil in a large pan over medium heat. Add the cumin and black mustard seeds, cooking until they start to pop, which should take about 1-2 minutes. Then, toss in the sliced onions and stir frequently for about 15 minutes, or until they turn soft and golden brown, forming the flavorful base of your filling.

Once the onions are caramelized, stir in the grated garlic, ginger, and finely diced green chili. Continue cooking for another 2 minutes, allowing the mixture to become fragrant and well-combined.

Add the ground spices along with the frozen peas to the pan. Cook everything together for about 5 minutes, stirring occasionally until the peas are heated through. Finally, add the cooled potatoes and a spoonful of lime pickle, mixing until everything is well incorporated. Set aside to cool completely.

While your filling cools, roll out the puff pastry on a lightly floured surface. Cut it into squares, large enough to hold the filling. Place a generous spoonful of the spiced mixture onto one half of each pastry square. Cut diagonal slits on the opposite side, brush the edge with egg wash (or coconut oil for vegan), and fold it over to seal tightly.

Preheat your oven to 190°C (375°F). Arrange the filled Spiced Pea and Potato Rolls on a baking sheet lined with parchment paper, ensuring they are spaced apart for even baking. Bake them for 15-20 minutes or until they are golden brown and puffed.