Dice up the onion and the bacon if you are using bacon strips. Melt some butter in a frypan and saute the onion and bacon. Put aside to cool.
Spray non-stick spray over the inside of a 20 cm pie dish and place one sheet of pastry on the bottom.
Spread cooked bacon and onion over the pastry and make a small well in the centre to put an egg.
Crack the eggs and gently place the eggs in each space.
Season with salt and pepper and them cover with finely chopped spinach.
Cover with the second sheet of pastry, seal the edges and create vent holes in the top sheet.
Baste the top of the pie with a beaten egg yolk and place in the oven for 15 minutes at 200 C.
After 15 minutes turn the oven down to 180 C and cook for a further 15 to 20 minutes, or until the top is golden brown.