Make the pizza dough according to the instructions on the packet, rolling it out into 4 long oblongs rather than circles. Leave in a warm place to prove for 15 minutes while you make the filling.
Preheat the oven to 220°C/fan 200°C/gas mark 8. Heat the olive oil in large pan and fry the onion, garlic and spices together for 6-8 minutes until soft. Add the spinach and cook for another 2-3 minutes until the spinach has wilted. Stir through the chopped tomatoes.
Scatter the spinach mixture over each base, ensuring you leave a 2cm gap around the edges. Evenly distribute the pine nuts and feta between the four bases, then finish with a light scattering of chilli flakes.
Dampen the edge of the dough with a bit of water and seal the edges of both ends to create a long boat shape, leaving the filling exposed in the middle. Place the pides on a lightly greased baking tray and bake for 15-20 minutes or until golden brown.