Peel the eggs and cut them lengthwise in half. Remove the yolks, season with salt and pepper, and mix with the rest of the ingredients. Fill the egg whites with this preparation. Serve very cold.
Wash and cut the lemons in half, empty them and set aside. Place the mackerel, lemon juice and olives in the blender glass. Beat to obtain a homogeneous compound. Pour the mixture into a bowl and add the mayonnaise, parsley, chopped onion and salt. Amalgamate well and place in a pastry bag with star nozzle. Fill the half lemons with the previous preparation and store in the refrigerator until serving time. Garnish with chopped parsley and serve with a grated carrot salad as a side dish.
Peel the eggs and cut them lengthwise in half. Remove the yolks, season with salt and pepper, and mix with the rest of the ingredients. Fill the egg whites with this preparation. Serve very cold.