Wash the potatoes and put them in a medium-sized pot. Cover the potatoes with water and boil them for 20 to 30 minutes, or until they're fork-tender.
While the potatoes are cooking, chop the parsley, dill, and scallions.
In a small bowl, mix the olive oil, vinegar, crushed garlic, mustard, salt, and pepper.
Let the potatoes cool for about 10 minutes then chop them up. Add them to a large bowl along with the parsley, dill, and scallions, and toss with the dressing. Chill the potato salad in the fridge or serve at room temperature.