Tip the panko breadcrumbs into a bowl, pour over the milk. Leave to rest for 5 minutes
Heat a drizzle of oil in a non-stick pan. Add the onion and fry for 5 minutes until soft. Stir in the spinach until wilted.
Add the beef mince to the breadcrumbs with the onion and spinach, crumbled feta, dried herbs and black pepper. Season with salt.
Use your hands to combine
Heat the oven to 190C fan
Cut the puff pastry in half lengthways and then in half widthways so you have 4 equal rectangles.
Place one of the rectangles vertically in front of you.
Place around 2-3 heaped dessert spoons of the filling lengthways down the centre of the pastry leaving a 2.5cm gap around the outside.
Flatten the filling out to around 1cm thick.
Starting in the top left corner cut 0.5cm-1cm wide diagonal strips into the pastry from the filling outwards. Repeat on the right hand side.
Trim the end pastry pieces a little so they fold neatly over the ends of the filling.
Fold the strips of pastry alternately into the middle crossing over each other.
When all the pastry is folded up and the filling is encased, gently press down the tops.
Brush with beaten egg.
Place the plaits on a lined baking tray.
Bake at 190C for 25-30 mins or until cooked through
