01 - Set the oven to 425°F to prepare it for roasting.
02 - Bring a large pot of salted water to a boil. Add potato chunks and cook for 8 minutes until tender but firm. Drain and let steam dry for 2 minutes.
03 - Place duck fat in a large roasting pan and put it in the oven for about 3 minutes to melt and heat.
04 - Add the parboiled potatoes carefully to the hot duck fat. Toss gently to evenly coat all pieces.
05 - Distribute smashed garlic, rosemary, thyme, salt, and pepper over the potatoes. Toss again to mix thoroughly.
06 - Roast in the oven for 40 to 45 minutes, turning once halfway through, until the potatoes are deep golden and crisp.
07 - Remove from oven, transfer to a serving platter, and serve immediately while hot.