Put a fry or saute pan on the stove, and put in the generous amount of butter or oil. Heat on high until sizzling.
In the meantime, crack an egg into a separate small bowl (this makes it easier to pour into the pan and create an even cook).
Once the pan is sizzling, pour the egg into the center of the butter or olive oil, and let it stay there.
Don't touch the egg, just let it cook on high for 2 minutes (runny yolk), 2 min 15 sec (medium yolk), or 2 min 30 sec (firmer yolk).
Turn off the stove, and let the egg set for a minute.
Pour onto the prepared avocado toast, plain toast, or enjoy on it's own!