Step 1

Prepare the dressing. In a small bowl, whisk together the garlic, vinegar, oregano, and red pepper flakes (if using). Season with a big pinch (about 1/2 teaspoon) of salt and pepper. Pour in the olive oil, whisking vigorously until emulsified. Set aside for now.

Step 2

Cook the potatoes. In a medium saucepan, cover the potatoes a couple of inches of water and set over medium-high heat. When the water is boiling, season liberally with salt. Boil until the potatoes are easily pierced with a fork, 10 to 15 minutes. Use a slotted spoon to transfer them to a large bowl to cool, leaving the boiling water on the stove.

Step 3

Blanch the green beans. Prepare an ice bath and set it next to your sink. Drop the green beans in the boiling water until just tender but still snappy, about 2 to 3 minutes, then drain and transfer to the ice bath to stop them from cooking further.

Step 4

Mix and dress. Add the potatoes and green beans to a large serving bowl. Add the tomatoes, onions, olives, and parsley. Pour the dressing all over the salad and gently toss to combine. Taste and adjust seasoning to your liking.

Step 5

Rest and serve. For best flavor, allow the salad to rest at room temperature for about 30 minutes. Or, cover and refrigerate for up to 2 days, allowing it to come to room temperature before serving.