1.Preheat oven to 240°C/475°F. Oil oven trays; line with baking paper.
2.Cook spinach in boiling water until just wilted; drain. Rinse under cold water; drain well. Chop spinach coarsely; combine in medium bowl with cheese. Season to taste.
3.Cook lamb, in batches, in heated oiled large frying pan until browned. Cut lamb fillets in half.
4.Stack four filo sheets, spraying individual sheets lightly with oil. Cut stack in half widthways; cover with a slightly damp tea towel to prevent drying out. Repeat process with remaining twelve filo sheets; you will have eight filo stacks.
5.Uncover one filo stack; place on board. Centre two pieces of lamb on stack, top with an eighth of the spinach mixture. Roll stack to enclose filling, fold in sides after first complete turn. Spray parcel with cooking oil; place on tray. Repeat.
6.Bake parcels, in oven, about 15 minutes or until fillo is browned lightly.
Serve with lemon and yogurt, if you like. Drain spinach well to stop pastry becoming soggy.Note