Make the hard-boiled eggs: Add eggs to a saucepan. Cover with water by 1 inch and bring to a rapid boil. Boil for 1 minute and immediately remove from heat. Cover and let rest for 10 minutes. Carefully remove eggs from the water and rinse under cold water. Once cooled, peel the eggs under running cool water and slice into quarters.

Prepare the potatoes and green beans: Slice the small potatoes in half, or in quarters if larger. Place them in a large pot and cover by 1 inch with water. Add 1 tbsp of salt and bring to a boil over medium-high heat. Once boiling, reduce heat to medium and simmer for about 12 minutes until potatoes are tender but not completely cooked. Add the green beans and continue to boil for another 2-3 minutes, until beans are crisp and potatoes can be easily pierced with a knife. Drain immediately into a colander and transfer into a large bowl of ice-cold water to stop the cooking process and retain the bright green color of the beans.

Make the vinaigrette: In a jar, combine the olive oil, lemon juice, vinegar, minced garlic, Dijon mustard, chopped capers, chopped black olives, salt, and black pepper. Shake well to combine.

Assemble the salad: In a serving bowl, add the chopped parsley and chives and mix with about half the amount of the vinaigrette. Add the cooked potatoes, green beans, and olives and toss to combine.

Finish and serve: Top the salad with the egg quarters. Drizzle the remaining dressing over the top (you may use all or less, to your preference). Season to taste, if needed. The salad is best after sitting for a few hours to allow flavors to meld. Enjoy at room temperature or cold.