Use a shamrock cookie cutter to cut out the center of your bread.
Melt the butter over medium heat in a skillet. Once it's melted, add your outer piece of bread.
Crack the egg and drop it into the shamrock shaped hole in your bread. Let cook 3-5 minutes, until the egg is almost completely set.
Use a spatula to flip the toast over in the pan, to lightly toast the other side and set the top of the egg. I just cook it about 30 seconds on the second side.
Place your egg in a basket on a plate, and let's start on the avocado toast.
Place your shamrock shaped piece of bread in the skillet to lightly toast it on both sides. You can turn off the stove once you've completed this step.
Remove the avocado from the peel, and mash it up. I find this is easiest to do in a cereal bowl with a fork.
Put your shamrock toast on the plate and place your cookie cutter back over it.
Dump the mashed avocado onto the toast and use your fork to spread it out so it covers the toast completely. Remove the cookie cutter and arrange your green shamrock on your plate with the egg in a basket.
Sprinkle a couple pinches of salt and pepper on both the egg and the avocado.
Approximate cost/serving: Even with the more expensive organic bread I use, this only came out to about 75 cents for a filling, protein packed breakfast. Gluten Free: I have tried this with gluten free bread to great success.