Pre heat the oven to 180 °C (356 F). Line a 20 cm x 27 cm slice tray with baking paper.
Place all of the ingredients into a bowl and stir until combined. *The bacon and onion can be fried in a pan first, but this is not essential.
Add the mixture to the baking tray and bake for 35-40 minutes, or until golden on top and cooked through. You can test the slice by inserting a wooden skewer into the middle. If it comes out clean, it is ready!
Remove the slice from the oven and rest in the tray for 15-20 minutes before gently placing the slice on a wire rack to cool.
The slice can be served warm, or sliced once it has cooled. Store in an airtight container for 3-4 days, or wrap and freeze for up to 3 months in a container.
