While your pastry is defrosting mix into a bowl the ricotta and egg then add crumbled feta cheese and pepper. Mix.
Chop up spinach and squeeze all the moisture out, pop in the ricotta mix bowl.
Cut pastry sheets in half left to right so you have 2 long rectangles. Divide ricotta mix vaguely into 4 portions. Along the middle of the long side add a portion of ricotta and spread evenly along pastry.
Brush milk along the edge of the pastry and carefully roll into a long tube, repeat with the others.
Carefully lift the long tube onto a lined baking sheet. Cut each tube with a sharp knife into the portion size you'd like, usually 4 or 6. If you're able to easily move a little apart do so but don't worry if you can't.
Brush with milk and sprinkle on the sesame seeds.
Bake for approx 15-20 minutes or until nicely browned.
Let cool for a minute or two and serve with sauce if needed.
Pre heat oven to 210-220*C