Peel and finely chop the onion, finely chop the sage. Coarsely grate the apple and Pecorino.
Heat the oil in a pan. Sauté the onion and sage for approx. 5 mins., transfer to a bowl and leave to cool.
Add the meat, apple and cheese, season and knead well.
Unfold the sheets of strudel pastry, cut lengthwise into thirds and then halve the pastry crosswise (makes 24 pieces).
Brush three pieces with a little oil, place one on top of the other slightly staggered.
Place 1/8 of the filling in the centre, fold the pastry over the top and press together gently, place on a baking tray lined with baking paper. Repeat this process with the remaining pieces of pastry and filling.
Approx. 15 mins. in the lower half of an oven preheated to 200°C.