Bake in a well greased 8 inch deep sided tin at 180oC until set, about 30 mins.
Alternative to bacon: salmon, tuna, mixed vegetables, mushrooms or anything you fancy (including leftovers). Things like mushrooms or capsicum are nicer when fried with the bacon and onion. You can pretty much add what you like to this recipe.
This can be cut up into squares of any size and served with salad, or cut into finger or bite size pieces for parties. Baking in a mini muffin or patty pan is good for parties. Serve hot or cold.