Step 1

Make the vinaigrette:

Step 2

In a jar with a tight-fitting lid, combine the oil, vinegar, garlic, mustard, oregano, salt and pepper, and shake together until thickened.

Step 3

Make the potato salad:

Step 4

Put the potatoes in a large saucepan and add enough cold salted water to cover them by at least 1 inch. Bring to a boil over high heat. Reduce the heat to medium-low and simmer until tender when pierced with a small knife, about 25 minutes.

Step 5

Drain and rinse under cold running water. Let stand until easy to handle. Peel, cut into bite-sized pieces, and transfer to a large bowl.

Step 6

Bring a medium saucepan of salted water to a boil over high heat. Add the green beans and cook them just until they turn bright green, 2 to 3 minutes. Do not overcook. Drain the green beans in a sieve and rinse under cold running water until they are cool. Add to the bowl with the potatoes.

Step 7

Sprinkle the warm potatoes with the vinegar and toss well. Season with 1 teaspoon salt and 1/2 teaspoon pepper. Add the cherry tomatoes, ripe olives, green olives, red onion, parsley, garlic and pepper flakes, and mix, adding the vinaigrette as you do so. Taste and season with additional salt and pepper, if needed.

Step 8

Serve immediately or cover and refrigerate until cold, about 2 hours.