Steak with Shallots and Lyonnaise Potatoes
3 tablespoons extra-virgin olive oil
3 large Yukon Gold potatoes (1 1/4 pounds), peeled and sliced 1/4 inch thick
1 large Vidalia onion, halved lengthwise and very thinly sliced crosswise
Kosher salt and freshly ground pepper
2 tablespoons red wine vinegar
Four 7-ounce sirloin steaks (1 inch thick)
2 tablespoons unsalted butter
4 large shallots, very thinly sliced
1/2 cup dry red wine
2 tablespoons finely chopped flat-leaf parsley
- In a very large nonstick skillet, heat 2 tablespoons of the olive oil until shimmering. Add the potatoes in a slightly overlapping layer and cook over moderately high heat, stirring occasionally, until golden and nearly cooked through, about 8 minutes.
- Add the onion, season with salt and pepper and cook, stirring occasionally, until tender, about 5 minutes longer. Add 1/2 tablespoon of the vinegar and gently toss to combine. Cover loosely and keep warm.
- Meanwhile, in another large skillet, heat the remaining 1 tablespoon of olive oil until shimmering. Season the steaks with salt and pepper and cook them over moderately high heat, turning occasionally, until browned and crusty, 8 to 10 minutes for medium rare. Transfer the steaks to a serving platter and keep warm.
- Add 1 tablespoon of the butter and the shallots to the skillet and cook over moderate heat until softened, about 5 minutes. Add the remaining 1 1/2 tablespoons of vinegar and cook until evaporated, about 30 seconds.
- Add the wine and cook until reduced by two-thirds, about 2 minutes. Remove from the heat and swirl in the remaining 1 tablespoon of butter.
- Add the parsley and any accumulated meat juices, season the sauce with salt and pepper and spoon over the meat. Serve the steaks at once with the potatoes.