Begin by preparing your ingredients: slice red onions, chop green onions, mince garlic, pit and halve olives, and chop parsley and dill.

Cut the potatoes into cubes, place in a pot with cold water and salt, and boil.

Create the vinaigrette by whisking together vinegar, mustard, oregano, garlic, salt, and pepper, then slowly drizzle in olive oil.

Transfer cooked potatoes to a mixing bowl, fold in remaining ingredients, and pour vinaigrette over.

Top with lemon zest and let sit for 15 minutes for flavors to meld before serving.