Preheat the oven to 450 degrees
Fill a large pot with water and add the potatoes and a generous pinch of salt. Bring to a boil and cook until potatoes are soft, about 20 minutes. Drain and let cool.
On a large sheet pan, add a drizzle of olive oil. Add the potatoes and smash them down flat with a cup covered with parchment paper. Brush with more olive oil and season with salt and pepper.
Bake for about 40 minutes, flipping halfway, or until golden brown and crispy.
In a large bowl, combine mayonnaise, mustard, green onion, celery, red onion, dill, paprika, salt and pepper.
Add the potatoes and toss to coat. Season with salt and pepper to taste.
Serve warm, room temperature or cold!
