Toast the bread: Heat a skillet over medium heat. Add a drizzle of olive oil and toast the sourdough bread until golden and crispy on both sides. Set aside.

Prepare the avocado: Cut the avocado in half, remove the pit, and scoop the flesh into a bowl. Mash it with a fork and season with salt and black pepper to taste.

Spread the avocado: Spread the mashed avocado evenly on the toasted bread.

Cook the egg: In the same skillet, heat a little more olive oil over medium heat. Crack the egg into the skillet and cook to your preferred doneness (sunny-side-up or over-easy).

Assemble: Place the cooked egg on top of the avocado toast.

Garnish and serve: Sprinkle with red pepper flakes (if using) and fresh cilantro or parsley. Serve immediately.