Scoop the avocado into a medium bowl. Season with salt and add the lemon juice. Mash until smooth.
2. Step
Cut out the center of the bread with heart-shaped cookie cutter. Set aside.
3. Step
Melt the butter in a medium skillet over medium-low heat. Add the heart and cut-out piece of bread and toast until golden brown, 2-3 minutes.
4. Step
Flip the bread, then crack the egg into the cut-out. Cover and cook for 1-2 minutes, until the white is set and the yolk is runny, or to your desired doneness.
5. Step
Transfer to a plate and spread the avocado over the heart.
