• Preheat the oven to 450°F. Line a large baking sheet with parchment paper or lightly grease it with olive oil.
• Place the potatoes in a large pot and cover with cold water. Season the water generously with salt.
• Bring to a boil and cook for 15–20 minutes, or until the potatoes are completely fork tender. Cooking time will vary depending on the size of the potatoes.
• Drain well and allow the potatoes to steam dry for about 5 minutes.
• Transfer the potatoes to the prepared baking sheet, leaving plenty of room between each one.
• Using the bottom of a glass or measuring cup, gently press down on each potato until it’s approximately ½-inch thick.
• Drizzle generously with olive oil. Season with kosher salt, garlic powder, onion powder and black pepper. Sprinkle with Parmesan, if using.
• Roast for 30–40 minutes, or until the potatoes are deeply golden brown with crispy edges. There’s no need to flip them.
• While the potatoes roast, make the creamy lemon garlic dip. Stir together the sour cream, mayonnaise, lemon juice, lemon zest, grated garlic and parsley. Season with salt and freshly ground black pepper. Refrigerate until ready to serve.
• To assemble, spread the creamy lemon garlic dip in a thick layer across the bottom of a large shallow serving platter.
• Arrange the hot crispy smashed potatoes over the dip, leaving some of the sauce visible around the edges.
• Finish with fresh parsley or chives and a pinch of flaky salt. Serve immediately while the potatoes are hot and crispy.

Recipe Notes

• Make sure the potatoes are completely tender before smashing. Undercooked potatoes are much more likely to fall apart.
• Allowing the boiled potatoes to steam dry helps remove excess moisture and creates crispier edges in the oven.
• Don’t overcrowd your baking sheet. Use two pans if necessary.
• For the crispiest potatoes, assemble the platter immediately before serving.
• The lemon garlic dip can be prepared up to 1–2 days ahead and kept refrigerated.