Step 1

Wash the potatoes, then put them into a large pot and cover with water. Bring to a boil over high heat, then add a tablespoon of sea salt.

Step 2

Allow the potatoes to boil until they're fork tender, about 25 minutes. Take the pot off the heat and keep the potatoes in the hot water for another 30 minutes.

Step 3

Remove the potatoes with a slotted spoon and place them in a strainer for another 20 minutes, or until they're cool enough to handle.

Step 4

Remove the potato skins with your hands or with a knife, then cut into thick slices and place in a glass serving bowl.

Step 5

Sprinkle the potatoes with the onion, parsley, and 1/2 tablespoon of sea salt.

Step 6

Add the vinegar and the olive oil, then adjust the salt to taste.

Step 7

Arrange the tuna and sliced hard boiled egg on top of the potatoes and enjoy!