Preheat oven to 425 degrees F.

Slice the bottom of the potatoes to where they will lay flat. Cut parallel slits about ⅛-inch apart into each potato about ⅔ the way down. Be careful not to cut completely through the bottom.

Brush the potatoes with bacon grease or other food oil and place in a cast iron skillet or casserole dish.

Bake for 20 minutes. Remove from the oven and slightly spread the slices apart with a knife to make sure they aren’t sticking together.

In a small bowl combine the butter, rosemary, garlic and onion powder. Brush the mixture generously over the potatoes. Sprinkle with margarita or sea salt.

Bake an additional 10 minutes. Remove from the oven, brush again with the butter mixture and bake another 10 minutes or until they are soft on the inside and crispy on top.

Remove from the oven and baste one more time, season with salt and pepper and serve immediately.