Instructions

• Peel the potatoes and slice them into 1/4-inch-thick rounds. Place the slices in a large pot, cover with cold water, and add salt to the water.
• Bring to a boil over high heat, then cook until the potatoes are just tender but still hold their shape, about 5 minutes. Drain in a colander and let sit briefly to steam-dry or pat dry with a kitchen towel.
• Heat a large skillet over medium heat and melt 2 tablespoons of the butter. Add the thinly sliced onion and cook, stirring occasionally, until the onion is soft and caramelized, about 15–20 minutes. Reduce the heat if the onions begin to brown too quickly.
• Remove the caramelized onions from the skillet and set them aside on a plate.
• In the same skillet, heat the remaining 2 tablespoons of butter and the 2 tablespoons extra-virgin olive oil over medium-high heat until the butter melts and the oil shimmers.
• Add potato slices in a single layer (work in batches if needed so they are not crowded). Cook until golden brown on the bottom, about 4–6 minutes, then flip and cook the other side until golden, another 4–6 minutes.
• Transfer each browned batch to a plate as it finishes and continue with the remaining potatoes.
• When all potato slices are browned, return all potatoes to the skillet along with the caramelized onions. Reduce heat to medium and gently toss or stir to combine and heat through, about 1–2 minutes.
• Season with salt and pepper to taste, sprinkle with the chopped fresh parsley, and serve.