Cook the Beef Bacon
Start in a cool pan. Layer the strips, overlapping slightly, and set over medium heat. As soon as fat starts rendering (pieces will start to curl) flip them every 30-45 seconds as they darken. When dark (but not burned), transfer to a paper-towel-lined plate or rack to drain and crisp up. Tent loosely with foil to keep warm.
Make the Egg in a hole
Using a cookie cutter, cut a hole in one slice of bread, then spread mayonnaise on one side of both slices. Fry the bread in the same pan. When browned on one side, flip both over and crack the egg into the hole. Fry for 2-3 mins, then turn down the heat and cover the pan until the white of the egg is set but the yolk is still runny. Remove everything from the pan.
Assemble
Spread the non-egg slice with the ketchup or salsa, add the bacon, then top with the egg slice. Halve and tuck in.