Preheat the oven to 450 degrees Fahrenheit (210 degrees Celsius).

Cut your potatoes into equal-sized chunks of about 2 inches wide and put in a heavy-bottomed stockpot with a lid. Cover the potatoes with water so that there's about an inch of water over the potatoes. Add a tablespoon of salt.

Put the potatoes on a large burner and turn the heat on high. Cover the pot and bring the potatoes to a boil (no need to stir!). Once the water starts boiling, let the potatoes cook for about 4-6 minutes until they can be pierced with a sharp knife but still have a little bit of crispness/resistance. Remove the pot from the heat and drain the potatoes.

Once the potatoes come to a boil, pour the fat into a baking sheet and slide it into the oven to let the oil heat for around 10 minutes.

Return the potatoes to the pot and cover again. With the lid on, cover the pot with a dish towel and grab both handles. Shake the pot back and forth, knocking the potatoes around so that they get all rough around the edges.

Carefully remove the baking sheet from the oven. Using tongs, carefully drop the potatoes into the hot oil, taking care to spread them into an even layer. Slide the baking sheet into the oven and roast the potatoes for 45-50 minutes. Check on the potatoes about halfway through, turning the potatoes with the tongs to make sure they brown evenly on all sides.

Remove the potatoes from the oven when they are golden brown and crisp. Transfer to a plate and sprinkle with another tablespoon of salt. Season with pepper and serve almost immediately.