Preheat the oven to 425ºF and place a large cast iron skillet in the oven.
Boil the potatoes until barely tender, then toss them in olive oil, smoked paprika, and salt before roasting in the skillet.
Mix together the ingredients for the sauce: mayonnaise, tomato paste, red wine vinegar, garlic, cayenne pepper, smoked paprika, and salt.
Drizzle the sauce over the roasted potatoes, sprinkle with parsley and flaky sea salt, then serve hot.
