01 - Fill a small saucepan with water and bring to a rolling boil. Gently lower the eggs into the water and boil for 8 to 10 minutes until fully set. Transfer the eggs to a bowl of ice water to cool, then peel and slice into rounds.
02 - While the eggs cook, toast the bread slices in a toaster or on a skillet until golden brown and crisp on both sides.
03 - Halve the avocado and remove the pit. Scoop the flesh into a small bowl and mash lightly with a fork to your preferred consistency. Season with fresh lemon juice, sea salt, and black pepper, then mix well.
04 - Divide the mashed avocado evenly between the two toasted bread slices and spread into an even layer.
05 - Cut the tomato into thin slices and arrange them over the avocado spread on each toast.
06 - Layer the sliced hard-boiled eggs over the tomatoes. Finish with a sprinkle of chopped chives or parsley and red pepper flakes if desired. Serve immediately while the toast is still warm and crisp.