Add the butter and oil to a non-stick pan over medium heat. Add the potatoes into it, and season with salt.
Cover the pan and cook for 12-15 minutes, until they are golden on the base side.
Uncover the pan and flip each potato to the other side and season with pepper. Cook uncovered for another 5-6 minutes, or until golden brown.
Notes
TO STORE: Place leftover potatoes in an airtight container and store them in the fridge for up to 3-4 days. TO FREEZE: Allow the potatoes to cool completely before transferring them to an airtight container or freezer-safe bag. Stored this way, they should last up to 6 months. TO REHEAT: Heat them in a skillet with some oil over medium heat until fully reheated. For maximum crispiness, you can also use an air fryer or preheated oven set to 180°C/350°F for 10-12 minutes or until they reach your desired temperature.