1. Preheat your oven to 450°F (230°C) and line a large baking sheet with parchment paper.
2. In a large pot, bring salted water to a boil. Add the potatoes and cook until fork-tender, about 15-20 minutes.
3. Drain the potatoes and let them cool slightly. Once cool enough to handle, place them on the prepared baking sheet.
4. Using a fork or the bottom of a glass, gently smash each potato until flattened but still intact.
5. Drizzle the smashed potatoes with olive oil and season with sea salt and black pepper.
6. Bake in the preheated oven for 25-30 minutes, or until the edges are golden and crispy.
7. While the potatoes are baking, prepare the dressing by whisking together the lemon juice, Dijon mustard, minced garlic, and 3 tablespoons of olive oil in a small bowl.
8. Once the potatoes are done, let them cool for a few minutes. Transfer to a serving bowl and toss gently with the dressing.
9. Sprinkle with chopped parsley, green onions, and feta cheese. Serve warm or at room temperature.

Cooking these potatoes brings back memories of Sunday family lunches, where each ingredient was a character in our culinary story. Remember, patience is key here—let the potatoes bake until they’re perfectly crispy for that delightful crunch we all love.