Heat olive oil in a nonstick skillet over medium heat.
Crack the egg into the skillet and cook until the whites are set and the yolk reaches your desired doneness.
While the egg is cooking, toast the bread slice to your preferred crispness.
Scoop out the avocado and mash it with a fork in a small bowl. Season with salt and pepper.
Spread the mashed avocado evenly over the toasted bread.
Top with the cooked egg and any additional toppings you like.
Serve immediately and enjoy!