Preheat the Oven: Preheat your oven to 425°F (220°C).

Prepare the Potatoes: Rinse the baby potatoes and place them in a large pot of salted water. Heat until bubbling and simmer until soft, roughly 15-20 minutes. Drain the potatoes and allow them to cool for a moment.

Smash the Potatoes: Once the potatoes are cool enough to handle, place them on a lined baking sheet. Use the bottom of a glass or a fork to gently press down on each potato until it's flattened but still intact.

Roast the Potatoes: Drizzle the potatoes with 2 tablespoons of olive oil and season with ½ teaspoon of salt and ¼ teaspoon of pepper. Roast the potatoes for 25-30 minutes, or until they are golden brown and crispy on the edges.

Make the Dressing: While the potatoes are roasting, prepare the dressing. In a medium bowl, whisk together the Greek yogurt, mayonnaise, Dijon mustard, lemon juice, minced garlic, and chopped parsley. Add salt and pepper to taste.

Combine Everything: Once the potatoes are crispy and ready, let them cool slightly. Toss them gently with the prepared dressing. You can either drizzle the dressing over the potatoes or stir them together in a large bowl.

Garnish and Serve: If desired, garnish the potato salad with thinly sliced scallions for an extra pop of freshness. Serve warm or at room temperature.