Lightly toast 6 pieces of bread. While this is toasting, wash lettuce and put a few leaves aside. Start slicing avocado and tomato, set aside.
Fry up the bacony goodness in a non-stick pan. I like my bacon well done, so fry on each side until crispy. Once bacon is finished, transfer to a plate with a paper towel. Fry the egg sunny side up, being careful not to let it get runny.
Assemble the sandwich, piece of bread then avocado and some mayo, another piece of bread and bacon, lettuce tomato, another piece of bread and more mayo, bacon and fried egg. Cut into it so egg yoke oozes down the sandwich.