1. Peel the parsnips and carrots and then cut them into 3" batons about 1/2" wide. Peel the onions taking care to leave as much of the root on as possible. Cut into quarters through the root, this will help the pieces to stay intact.
2. Core the peppers and cut into 1/2" batons.
3. Take the seeds from the cardamom pods and crush them along with the cumin seeds and the saffron. Mix in the oil and then toss all the prepared vegetables in this.
4. Spread the vegetables and the oil in a roasting dish and cook in a hot oven 200°C 400°F gas 6 for 30 minutes or until they are cooked through and lightly coloured.
5. Using a slotted spoon lift the vegetables from the dish reserving the oil.
6. Meanwhile bring a large pan of well salted water to the boil and when it's simmering blanch the baby corn for 2 minutes timing from the moment that the water returns to the boil. Lift from the pan and drop into iced water. Pull the strings from the mange tout and cut the courgettes in half lengthways and blanch these in the same way, again cooling in the iced water.
7. Drain and leave to dry for a few moments on a clean tea towel.
8. Pour the oil into a small saucepan and scrape in the spices. Season well and add the butter, heating until it is melted.
9. Line a baking sheet with non-stick paper.
10. Open the filo pastry and unfold. Brushing each sheet with butter gradually build up a square of filo about 24" across, making sure the centre, which will be the base of your pie, is several sheets thick.
11. Now layer half the parsnip mixture in an 8" circle in the centre of the pastry. Lay the blanched vegetables on top building them up to form an even tower. Lay the remaining parsnip mixture on top again spacing and mixing the vegetables evenly. Season with salt and pepper and drizzle over the balsamic vinegar.
12. Brush the edges of the pastry with butter and fold over making a rough but complete lid. Now drizzle the remaining butter and spices over the pie gently brushing to make sure the whole outer layer is coated with the mixture. Sprinkle on the sesame seeds and chill until needed.
13. To cook the bastilla heat the oven to 200°C 400°F gas 6 for 25-35 minutes or until a rich golden brown.