Bring a large pot of water to boil and cook potatoes cubes for about 7 to 8 minutes.The potatoes are done when tender and the tip of a knife easily slides into the center of a cube.
Turn off the heat and drain the potatoes through a colander. Shake out the excess water and transfer the cooked potatoes to a large mixing bowl.
In the meantime, put the eggs in medium saucepan and cover with cold water by a ½-inch. Bring to a gently boil over medium-high heat. When the eggs start rattling against the bottom of the pan, turn off the heat, cover with a lid, and let sit for 7 - 8 minutes.
When the eggs are through cooking, place the saucepan under cold running water for about 3 minutes, long enough to stop the cooking.
To make the vinaigrette, in a small mixing bowl, add lemon juice, ¼ cup chopped parsley and sea salt. Using a small whisk (or a fork), slowly whisk in the olive oil.
Pour the vinaigrette over the potatoes and season to taste with more salt and pepper, as needed.
Using a wooden spoon, stir in ¾ of the scallions and the rest of the parsley.
Transfer the potatoes to a serving bowl and top with tuna.
Drain the boiled eggs and carefully peel. Once peeled, rinse the eggs under cold water to remove any remaining bits of shell. Slice the eggs and arrange on the top of potatoes and tuna.
Sprinkle with remaining scallions and parsley before serving.
Notes
One serving yields 380 calories, 26.5 grams of fat, 15 grams of carbs and 19 grams of protein.