Drizzle a lug of oil into a large non-stick frying pan over a medium heat, add the onion, Korma Curry Powder, Cumin and cook for 8 minutes, or until softened but not coloured. Stir in the Garlic, Ginger, Fennel, Ground Coriander and the leftover roast veg. Mix well and then crush gently with a potato masher – don’t overdo it: you want a fairly chunky mixture. Leave to cool.
Preheat the oven to 180°C, 350°F, Gas Mark 4
Unroll the filo pastry and cover with cling film and a damp tea towel. Peel off one piece and keep the rest covered so that it doesn’t dry out.
Lay the pastry sheet flat on a clean surface and brush with melted butter. Fold in one third lengthways towards the middle. Brush again with the butter and fold in the other side to make a long triple-layered strip.
Place one rounded teaspoon of the filling mixture at one end of the strip, leaving a 2 centimetre/ 1 inch border.
Take the right corner and fold diagonally to the left, to enclose the filling and form a triangle.
Fold again along the upper crease of the triangle. Keep folding in this way until you reach the end of the strip.
Brush the outer surface with more butter.
Place onto a baking sheet and cover while you make the rest of the samosas. Sprinkle over a few sesame seeds, if using.
Bake in the centre of the oven for 30-35 minutes, or until golden and crisp, turning halfway through the cooking time.
Serve samosas on a sharing plate with a bowl of chutney.