Spicy chicken samosas

Name: Spicy chicken samosas
Ingredients: 2 tbsp vegetable oil, plus extra for deep-frying; 100g/3½oz onion, finely chopped; 2 green bird’s-eye chillies, finely chopped; 2.5cm/1in fresh root ginger, peeled and finely chopped; 3 garlic cloves, finely chopped; 1 tbsp tomato purée; 250g/9oz chicken mince; ½ tsp ground cumin; 1 tsp Kashmiri chilli powder; ½ tsp turmeric; 1 tsp ground coriander; 2 tbsp malt vinegar; 1 tsp sugar; handful fresh coriander, finely chopped; 3 tsp plain flour; 270g pack filo pastry (7 sheets); salt