Wash the spinach well and remove the stalks. Bring a large pan of salted water to the boil and plunge in the spinach leaves for just a minute, until limp. Drain well, pressing out all the liquid you can, then chop up small. Cut up the chicken into small pieces, removing any skin. Peel the garlic and chop finely. Peel the onions and chop into fairly small pieces.
Heat the oil and 15 g/½ oz of the butter in a large frying pan. Add the chicken and stir around over a high heat for about 5 minutes, until lightly browned. Then add the garlic, onions and spices and stir for another minute. Cover the pan tightly with foil and leave just bubbling over a low heat for 30 minutes, stirring round now and then, especially towards the end when the juices evaporate. If the juices don’t evaporate completely, remove the foil, increase the heat and bubble until they do. Remove the pan from the heat and season with salt and black pepper. Stir in the marmalade. Lastly, stir in the chopped spinach and leave until cold.
Preheat the oven to 180°C/350°F/gas mark 4. Melt the remaining butter in a saucepan. Brush a deep, loose-based, 19 cm/7½ in round cake tin thinly with melted butter. Lay a whole sheet of filo pastry in it, press it down in the tin and let the ends hang right over the sides. Brush the pastry thinly with butter. Lay another sheet across the other way so that the tin is completely lined. Continue like this in layers, buttering each sheet and letting the pastry hang out all round the edges of the tin. Spoon in the cooled chicken mixture. Bring in the overlapping pastry sheet by sheet, loosely over the top, lightly buttering each piece. The top 2-3 layers should be completely crumpled, sticking up towards the centre.
Cook the pie in the centre of the oven for 30 minutes, until the top is well browned. Then put the tin on a narrower, round object (such as a tin of tomatoes) and push the pie up and out of the tin. Using a wide spatula, lever it carefully off the base on to an ovenproof serving plate and put it back in the oven for another 20-30 minutes to brown the sides and crisp up the base.