Preheat oven to 180 C and place a tray in to heat.
Grease and lightly flour a 20x30cm baking tin/dish. Line base and sides with pastry and cut out a lid. Chill for 15 minutes.
Saute onions until partially softened. Cool.
Sprinkle onions over pastry base. Lay bacon rashers in an even layer over onion. Break eggs over bacon, evenly distributed. I prefer to break yokes too but you may choose not to. Sprinkle over parsley, season with salt and pepper. Use a small pastry brush and dip into eggs and brush pastry edges. Add another layer of bacon then cover with pastry lid, pressing edges to seal.
Brush top with egg wash, make a few slits to allow air to escape during cooking.
Place on pre-heated tray and cook for 30-40 minutes until golden brown on top and base is cooked.
Slice and eat!
