Preheat a skillet on medium heat and cook your bacon. Lower the heat to medium-low and add the eggs to the pan and cook sunny side up, over-medium or over-well.
Toast the sourdough and spread with the mashed avocado or guacamole. Put two pieces of bacon on the sandwich and then the egg.
Notes
You can use any type of bread you want and you can also poach the eggs. Sliced tomatoes also taste great on this sandwich.