Preheat your oven to 425°F / 220°C.
Place the halved potatoes and sliced onion on a large baking sheet.
Drizzle with olive oil, then sprinkle with smoked paprika, garlic powder, onion powder, sea salt, and black pepper.
Toss everything together with your hands or a spatula until evenly coated.
Arrange the potatoes in a single layer, turning as many as possible cut-side down for the best browning.
Roast for 20 to 25 minutes, until the potatoes are golden brown, crisp on the outside, and tender when pierced with a fork.
Remove from the oven, stir in the fresh chopped scallions, and serve warm.
Don't be afraid of the high oven temperature.
Roasting at 425°F / 220°C is crucial for achieving that perfectly golden exterior and fluffy interior.