Make Hard-Cooked Eggs: Place 4 to 6 eggs in a large saucepan, cover with cold water by 1 inch and bring to a simmer. Cover, remove from the heat and set aside, 8 to 10 minutes. Drain, then peel in a bowl of cold water. Halve and scoop out the yolks. Mash with 3 tablespoons olive oil, a can of tuna, chopped parsley and a splash of lemon juice. Scoop into the whites; top with sliced olives and tomatoes.