Wash your potatoes and peel them. Slice them evenly.
Slice onion.
Place the sliced potatoes and onions in a medium bowl.
Next, heat your seasoned cast iron skillet on medium heat.
Add the vegetable oil or bacon grease, letting it warm and shimmer.
Using bacon grease infuses our skillet fried potatoes and onions with an added depth of flavor.
Note: Wait for the oil to shimmer but not smoke. If unsure, drop a small potato slice; if it sizzles immediately, the oil is ready.
Once the oil is hot add the potatoes and onions, sprinkle with salt and pepper.
Cover and let the potatoes and onions sizzle undisturbed for around 4-5 minutes or until they flaunt a golden-brown hue.
Gently flip, cover, and repeat for the other side, cooking for about 3-4 minutes. Depending on the size you slice your potatoes and the heat you're cooking them you may need to cook them a bit longer. It varies.
Once you've got that beautiful golden brown on both sides and they are tender, take them out of the skillet and set them on a plate lined with paper towels.