01 - Place eggs in a saucepan and cover with cold water. Bring to a rolling boil over medium-high heat, then cover the pan, remove from heat, and let stand for 9 to 10 minutes. Transfer eggs to a bowl of ice water to cool completely before peeling and slicing into rounds.
02 - Toast the bread slices in a toaster or on a skillet over medium heat until golden brown and crisp on both sides.
03 - While the bread toasts, halve the avocado and remove the pit. Scoop the flesh into a mixing bowl and add the lemon juice, salt, and black pepper. Mash with a fork until the mixture is creamy but retains some texture.
04 - Divide the mashed avocado evenly between the two warm toast slices, spreading it to the edges in an even layer.
05 - Arrange tomato slices over the avocado spread, then layer the sliced hard-boiled eggs on top.
06 - Drizzle with extra-virgin olive oil if desired. Season with additional salt, pepper, fresh herbs, and crushed red pepper flakes. Serve immediately while the toast is still warm and crisp.