Heat the oil and butter over medium heat in a nonstick 10-inch skillet. Once the butter is melted, sprinkle the grated potatoes into the pan in an even layer and, using a spatula, gently press them into the pan. Season with about half of the salt and pepper and let the potatoes cook without shaking or stirring the pan, until they're crisp and browned on the bottom, 8 to 10 minutes.
Slide the potato cake onto a large plate and invert it onto another plate. Slide the potato cake back into the pan, browned side up, and season the top with the remaining salt and pepper. Continue to cook until the underside is nicely browned and the potato cake is cooked through, 7 to 9 minutes longer.
Slide the potato cake onto a cutting board. Cut into wedges, sprinkle with parsley, and serve.
Copyright (c) 2012 Ten Dollar Dinners by Melissa d'Arabian