In a large pot of salted water, boil the potatoes until they are just about fork tender. Do not overcook. Drain the potatoes and cool. Slice the potatoes about 1/4-inch thick.
In a large, heavy-sided cast iron skillet, add the shortening, onions, and potatoes and cook over medium heat until golden brown. Season with salt and pepper, to taste.
This recipe was provided by a chef, restaurant or culinary professional. It has not been tested for home use.