Peel the hard boiled eggs and place them in a medium size bowl. Using a fork, mash the eggs against the sides of the bowl until they are broken up. Add the mayo and chives.

Peel the avocado and discard the pit. Dice half of the avocado and add it to the eggs. Mash the other half of the avocado in a small bowl, then add it to the egg salad as well and mix everything together until combined.

Season the egg salad with salt and pepper, then taste, adjusting seasoning as needed.

Assemble the sandwich by dividing the ham between two of the slices of bread. Top with egg salad divided between each sandwich, then place the remaining bread slices on top to make two sandwiches. Slice and enjoy!