The sweet-and-tangy bite of onions brings out the best in good steaks. The chef in a steakhouse might caramelize the onions over low heat for hours. We wanted a quick cooking alternative. Here’s what we discovered: Test Kitchen Discoveries Choose meaty strip steaks for an intensely beefy flavor. Cook them over medium-high heat in a heavy-bottomed skillet to achieve the best sear. Resist temptation and don’t move the steaks while they cook. A well-browned crust requires patience--moving will break the connection between steak and pan and disrupt the searing process. Skip a long, slow sauté for the onions. Brown the onions quickly, and then simmer them in a balsamic vinegar and brown sugar mixture. The shortcut produces nearly identical results to slow cooking. Simmer the minced rosemary in the sauce to soften it. Uncooked rosemary can be unpleasantly chewy. Prepare the steaks and sauce in the same pan. The browned bits left behind by the steaks lend a deep meaty flavor to the sauce.more
Adapted from cookscountry.com
The cooking times here yield medium-rare steaks. Because the sauce is so rich, we think three steaks (the maximum you can fit comfortably in a large skillet) will feed four people when sliced thin.
tablespoons vegetable oil
large red onions , peeled and cut into ½-inch rounds, rings separated
boneless strip steaks (8- to 10-ounce), 1 to 1¼ inches thick
cloves garlic , minced
cup balsamic vinegar plus 1 additional tablespoon
teaspoon minced fresh rosemary
tablespoon light brown sugar
1. Heat 2 tablespoons oil in large skillet over medium heat until shimmering. Add onions and 1/2 teaspoon salt and cook, stirring frequently, until lightly browned, about 10 minutes. Transfer onions to bowl. Wipe out skillet with paper towels. 2. Add remaining 1 tablespoon oil to skillet and cook over medium-high heat until just smoking. Meanwhile, pat steaks dry with paper towels and season with salt and pepper. Cook steaks, without moving, until browned on first side, 4 to 5 minutes. Flip steaks and continue to cook until browned on second side, 3 to 4 minutes more. Transfer steaks to plate and wrap with foil. 3. Discard fat in skillet, return onions to pan, and set over medium heat. Add garlic and cook until fragrant, about 30 seconds. Add 1/2 cup vinegar, rosemary, and brown sugar and cook, scraping up browned bits with wooden spoon, until thick and syrupy, about 2 minutes. Pour any accumulated steak juices into pan along with remaining 1 tablespoon vinegar. Season with salt and pepper. 4. Slice steaks crosswise into 1/4-inch slices and transfer to platter. Spoon onions and sauce over steak. Serve.