Preheat the oven to 200°C, fan 180°C, gas 6. In an ovenproof frying pan, heat 1 tbsp of the oil and cook the peppers and potatoes with the garlic and oregano for 2-3 minutes.
Tip the mixture into a large bowl, add the feta, artichokes, pesto and half the pine nuts.
Wipe the frying pan with kitchen paper, thenline with the 6 filo pastry sheets, overlapping and brushing each layer with the remaining oil.
Pour in the vegetable mix, followed by the remaining pine nuts, the tomatoes and cheese. Cook on the hob over a medium heat for 3-4 minutes, then transfer to the oven and bake for 10-15 minutes, until golden.