Cut the avocado in half, remove the pit, and scoop out the flesh.
Boil the eggs, peel them, and chop them finely.
Place the avocado and eggs in a bowl and mash them together.
Add mayonnaise, salt, and pepper, and mix well.
Optionally, add lemon juice and thinly sliced onion, then mix again.
Serve on a plate as a salad.