Make sure you have prepared all of your ingredients ahead of time.
Cook your egg in a skillet with the melted butter. I went sunny side up, but my wife wanted her eggs scrambled, which I so kindly made for her. So cook your egg however you like them.
To the bottom piece of toast, lather on the mayonnaise. Next layer on the bacon, covering the bottom of the toast.
Add the torn lettuce, slices of tomatoes, and top with the cooked egg.
To the other piece of toasted bread, spread on the avocado.
Add the avocado bread to the top of the egg, and as it may slide a bit, take a butter knife and insert it to the middle of the bread, going all of the way through.