Preheat the oven to 425°F (220°C).
Wash and peel the potatoes, then cut them into even chunks.
Place the potato chunks in a large pot and cover with cold water.
Add a pinch of salt and bring the pot to a boil.
Boil the potatoes for about 10 minutes until just tender but not falling apart.
Drain the potatoes and let them steam dry for a few minutes.
In a large mixing bowl, toss the potatoes with olive oil, salt, pepper, garlic powder, and rosemary.
Spread the potatoes out in a single layer on a baking sheet.
Roast in the preheated oven for 25-30 minutes, flipping halfway.
Remove from the oven and let them cool slightly before serving.