argentine stuffed rolled flank steak (matahambre)


1 2½-pound flank steak, trimmed of excess fat

kosher salt

freshly ground black pepper

1 cup milk

2 cups Swiss chard leaves, well rinsed and coarsely chopped

2 carrots, shredded

3 large hard-cooked eggs, peeled and quartered lengthwise

½ cup large pitted green Spanish olives, halved lengthwise

½ small yellow onion, sliced into thin rings

1³ cup small pickled hot peppers, such as Goya, drained and chopped

¼ cup freshly grated Parmesan cheese

1 tablespoon olive oil

1 cup hearty red wine, preferably Argentine malbec

1 cup reduced-sodium beef broth

1 large yellow onion, cut into 4 wedges

¼ cup fresh flat-leaf parsley, chopped

1 head garlic, cut in half

6 fresh thyme sprigs

6 fresh oregano sprigs

2 bay leaves

3 tablespoons all-purpose flour

¼ cup water

Place the steak on a cutting board with the grain running toward you. Holding a thin sharp knife parallel to the board and starting at one long side, butterfly the steak: Cut with the grain almost to the other side, and open up the steak like a book. Place a piece of plastic wrap over the meat. Gently pound with a meat mallet or rolling pin until the meat is evenly thick. Season with ½ teaspoon salt and ¼ teaspoon pepper. Place the meat in a small shallow baking dish and pour in the milk. Cover with plastic wrap and refrigerate for 4 hours or overnight.
Pour off the milk and pat the steak dry with paper towels. Place the meat on a work surface. Scatter the Swiss chard evenly over the top, leaving a 1-inch border. Sprinkle the carrots evenly over the Swiss chard. Top evenly with the eggs, olives, onion slices, pickled peppers, and cheese. From a short side, carefully roll up the meat jelly roll style. Tie with kitchen string at 1-inch intervals.
Heat the oil in a Dutch oven over medium-high heat. Add the meat roulade and cook, turning occasionally, until browned on all sides, about 5 minutes. Add the wine, broth, onion wedges, parsley, garlic, thyme, oregano, and bay leaves and bring to a boil. Reduce the heat to medium low and cover. Simmer until the meat is fork tender, about 1½ hours.
Transfer the meat to a cutting board. Tent with aluminum foil and let stand for 15 minutes.
With a slotted spoon, remove and discard the garlic, herb stems, and bay leaves from the cooking liquid. Bring to a simmer. Whisk together the flour and water in a small bowl until smooth. Gradually whisk the flour mixture into the simmering liquid, and return to a simmer. Cook, whisking often, until the sauce has no raw flour taste, 3 to 4 minutes. Season with salt and pepper. Pour into a large sauceboat.
Remove the strings and cut the roulade crosswise into ½-inch-thick slices. Serve the matahambre with the sauce.