In a mixing bowl, combine the all-purpose flour and salt. Mix well.

Add the vegetable oil and rub it into the flour until the mixture resembles breadcrumbs.

Gradually add water, a little at a time, and knead to form a smooth, firm dough. Cover with a damp cloth and let it rest for at least 30 minutes.

Heat oil in a pan over medium heat. Add cumin seeds and let them sizzle for a few seconds.

Add the mashed potatoes and green peas to the pan. Mix well.

Stir in the coriander powder, garam masala, turmeric powder, red chili powder, and salt. Cook for a few minutes until heated through.

Remove from heat, and add chopped cilantro and lemon juice. Mix well and let it cool.

Divide the dough into small balls (about the size of a golf ball). Roll each ball into a thin oval or circle on a lightly floured surface.

Cut the rolled dough in half to form two semi-circles. Take one semi-circle and form a cone by bringing the straight edge together, sealing the edge with water.

Fill the cone with the prepared filling, then seal the open edge by pressing it together with your fingers, ensuring there are no gaps.

Heat oil in a deep frying pan over medium heat. Once hot, carefully add the samosas in batches.

Fry until golden brown and crispy, turning occasionally for even cooking. Remove using a slotted spoon and drain on paper towels.

Serve hot with mint chutney or tamarind sauce.