450g (1 lb) maida or plain (all-purpose) flour
1 teaspoon salt
4 Tablespoons oil or ghee
400g (14 oz) potatoes, cut into quarters
80g (1/2 cup) peas
1 1/2 teaspoons cumin seeds
1/2 teaspoon coriander seeds
2 Tablespoons oil
1/2 onion, finely chopped
1/4 teaspoon ground turmeric
1/2 teaspoon garam masala
2 green chillies, chopped
3 cm piece of ginger, chopped
1 1/2 Tablespoons lemon juice
2 Tablespoons chopped coriander (cliantro) leaves
oil, for deep-frying
To make the pastry, sift the maida and salt into a bowl, then rub in the oil until the mixture resembles breadcrumbs. Add 180-200ml (3/4-1 cup) warm water, a little at a time, to make a pliable dough. Turn out onto a floured surface and knead for 5 minutes, or until smooth. Cover and set aside for 15 minutes.
To make the filling, cook the potato in simmering water for 10 minutes, or until tender. Drain and cut into small cubes. Cook the peas in simmering water for 2 minutes. Drain and refresh in cold water.
Place a small frying pan over low heat, dry-roast the cumin seeds until aromatic, then remove. Dry-roast the coriander seeds. Grind 1/2 teaspoon of the cumin and all the coriander to a powder in a spice grinder or a mortar and pestle.
Heat the oil in a heavy-based saucepan over low heat and fry the onion until light brown. Stir in all the cumin, the coriander, turmeric and garam masala. Add the potato, chilli and ginger and stir for 1 minute. Mix in the lemon juice and coriander leaves and salt, to taste, then leave to cool.
On a floured surface, roll out one-third of the pastry to a 28cm (11 in) circle, about 3mm (1/2 in) thick. Cut 10 circles with an 8cm (3 in) cutter and spoon 1/2 Tablespoon of filling onto the centre of each. Moisten the edges with water, then fold over and seal with a fork into a semicircle. Repeat to use all the filling and pastry. Fill a karhai or a heavy-based saucepan to one-third full with oil and heat to 180c (350f/Gas 4), or until a cube of bread fries brown in 15 seconds. Fry a few samosas at a time until browned. Turn and fry the other side. Drain on a wire rack for 5 minutes before draining on paper towels.