Place the peanuts in a strainer or colander, and rinse under water. Spread them out in a single layer to air-dry for at least 30 minutes.
In a clean wok, add in the air-dried peanuts and enough oil to just cover the peanuts. Then turn on the heat to medium low. Gently and slowly push the peanuts around to heat them evenly and prevent burning.
You’ll first see small bubbles forming in the oil, and then some steam as the moisture in the peanuts cooks off. Then you’ll begin to hear small popping noises coming from the peanuts. They should be done once that popping sound stops and the pink skins on the peanuts turn a mahogany brown. Because the peanuts can burn easily, it’s a good idea to turn off the heat for the last 1-2 minutes of cooking. This allows the peanuts to continue to cook in the hot oil without the risk of burning.
Turn off the heat, strain the peanuts out, and spread them out on a baking sheet to cool completely. Sprinkle with salt, and serve.
Store any leftovers in an airtight container. Be sure to strain the oil and save it. It will have a light peanut flavor and is great for cooking.