Scoop out some of the avocado from the pitted area to widen the “bowl” area.
Place the scooped avocado into a medium-size mixing bowl.
Mash it with a fork.
Add the tuna, olives, onion, bell pepper, and parsley to the mixing bowl.
Stir it all together until everything is well mixed. Taste and add salt and pepper as needed. You may not need any salt, as the olives make this salty enough for me.