Preheat the oven to 200°C and grease a baking tray.
Fry the sliced onion in oil for five minutes until softened.
Melt 150g of butter and cook mushrooms, garlic, and thyme until softened.
Mix the cooked vegetables with artichokes and pine nuts in a bowl.
Season the mixture, let it cool, and drain through a sieve.
Melt the remaining butter and layer two sheets of filo pastry on the tray.
Brush the pastry with butter and add another two layers of filo.
Add the final pastry layers and brush only the edges with butter.
Place the filling on the pastry, roll it into a parcel, and secure the ends.
Brush the roll with butter and bake for 25 minutes until golden.