Kids will love folding the filo pastry and filling into triangles. They are made healthier by baking rather than frying.
Peel the potatoes and chop into chunks. Boil for 12 minutes. Drain and crush. Set aside.
Finely chop the onion. Peel and grate the ginger. Set aside.
Heat the vegetable oil in a saucepan and fry the mustard seeds until they begin to pop.
Add the onion and ginger. Fry for 2 minutes.
Add the frozen peas, ground coriander, ground cumin, lemon juice, and salt. Cook for 2 minutes.
Add the crushed potatoes. Cook for 2 minutes. Season to taste. Set aside and leave to cool.
Pre-heat the oven to 180C. Unroll the filo pastry and cover with cling film and a damp tea towel. Peel off one layer and keep the rest covered so that it doesn’t dry out.
Lay the pastry flat on a clean surface and brush lightly with melted butter. Fold in one-third of the pastry lengthways towards the middle. Fold in the other side to make a long triple-layered strip.
Place one rounded teaspoon of the mixture at the left end of the strip, leaving a small boarder. Take the bottom left corner and fold diagonally to the right, enclosing the filling tightly and forming a triangle. Fold again along the upper crease of the triangle. Keep folding like this until you reach the end of the strip.
Brush the outer surface with a little more butter. Place onto a baking sheet. Sprinkle over the sesame seeds.
Bake in the oven for 25 minutes, until golden and crisp.