Toast the bread: Choose slices about 1/2-inch thick. Toast until crisp at the edges and golden in the center.
You want sturdy support for the toppings.
Prep the avocado: Scoop the avocado into a bowl. Add lemon juice, a pinch of salt, and a few grinds of pepper. Mash gently with a fork until mostly smooth but still a little chunky.
Cook the eggs your way: Heat olive oil or butter in a nonstick pan over medium.
Crack in both eggs. For sunny-side up, cook until whites are set and yolks are runny. For over-easy, flip briefly.
For scrambled, whisk eggs with a pinch of salt, then cook low and slow until soft and creamy.
Build the base: Spread the mashed avocado evenly over the hot toast. Taste and adjust with more lemon or salt if needed.
Add the eggs: Place one egg on each slice, or stack both on one slice for a tall, diner-style situation.
Season and finish: Sprinkle with red pepper flakes, everything seasoning or sesame seeds, and fresh herbs. Drizzle with a few drops of olive oil if you like.
Finish with one last pinch of salt and pepper.
Serve right away: Add cherry tomatoes or arugula on the side for brightness and crunch.