Season the meat on all sides and in the place that the bone occupied previously, put the crumbled MEVGAL Feta Cheese, the onions, and the MEVGAL PARADOSIAKO Kasseri Cheese. Sprinkle with the chopped garlic.
Lay the pastry sheets in a buttered baking dish, brushing each sheet on both sides with butter. Place the lamb in the middle and pull the sheets together to seal it in. Pour over the rest of the butter. Bake for 1 hour 15 minutes with the roll covered with tinfoil. Remove the tinfoil for the last 15 minutes to allow the meat to brown. Serve cut into slices.