How long does par boiled potatoes take to roast in a oven?

Parboiled potatoes typically take about 20 to 30 minutes to roast in a preheated oven at 400°F (200°C). To achieve a crispy exterior, it's recommended to toss them in oil and seasonings before roasting. Make sure to check for doneness by piercing them with a fork; they should be tender inside and golden-brown outside. Adjust the time as needed based on the size of the potato pieces.