Mix flour and salt in a bowl, then stir in oil and egg yolk to create breadcrumbs.
Gradually add warm water to form a smooth elastic dough, then chill in the fridge.
Coat chicken breasts in a mixture of tandoori paste and yoghurt and marinate for one hour.
Preheat the oven to 180°C.
Roast chicken for 20 minutes until translucent juices run clear, then cool and cube.
Boil potatoes for 15 minutes, drain, cool, and finely chop.
Fry onions in oil until soft, then stir in turmeric, garam masala, mustard seeds, and seasoning.
Add garlic and chillies for 3 minutes, then cook curry leaves and potatoes for 10 minutes.
Stir in peas for 3 minutes, then fold in chicken, lemon juice, and coriander before cooling.
Roll pastry 3mm thick and cut into 15cm rounds, سپس bisecting each into semicircles.
Form cones from semicircles, seal with egg white, fill half-way, and seal the tops.
Deep fry samosas in batches for 5 minutes until golden and drain on paper.
Serve warm with chutney and raita.