Instructions

• Peel the potatoes and slice them into 1/4-inch-thick rounds. Place the slices in a pot, cover with water, add salt to the water, bring to a boil, and cook until the potatoes are just tender but still hold their shape, about 5 minutes. Drain the potatoes and pat them dry with paper towels or a clean kitchen towel.
• In a large skillet, melt 2 tablespoons of the butter over medium heat. Add the thinly sliced onion and cook, stirring occasionally, until the onions are soft and deeply golden/caramelized, about 15–20 minutes. Transfer the caramelized onions to a plate and set aside.
• In the same skillet, add the remaining 2 tablespoons of butter and the 2 tablespoons of olive oil. Heat over medium-high until the butter is melted and the oil is shimmering.
• Working in a single layer (cook in batches if necessary so the slices do not crowd), add potato slices to the skillet and cook until the bottoms are golden brown, about 5 minutes. Flip each slice and cook the second side until golden brown, about 5 minutes more. Transfer each finished batch to a plate while you cook the remaining potatoes.
• When all potato slices are browned, return all the potatoes to the skillet, add the caramelized onions, and gently toss or stir to combine and heat through.
• Season to taste with salt and pepper, sprinkle with the chopped fresh parsley, and serve.