Two 12-oz strip steaks, each about 1-inch thick
3 tablespoons cider vinegar
2 tablespoons olive oil
1 large Spanish onion, cut in half, then sliced thin
Pat the steaks dry. Lay them in a deep bowl and sprinkle enough of the adobo over both sides of the steaks to coat them evenly.
Pour the vinegar into the bowl and swish it around to coat the bottom. Let the steaks soak up the vinegar until they start to change color on the underside, about 15 minutes. Flip them over and let them stand another 15 minutes.
Heat the oil in a heavy skillet over medium-high heat. To cook steaks of this size to medium rare, cook 6 minutes on the first side, flip them over and cook 4 minutes on the second side. Take the steaks out, add a little splash of olive oil if the pan looks dry, and add the onions. Cook, tossing the onions around, until they are richly browned but still fairly crisp. Because of the color left in the pan from the steaks, they will brown pretty quickly, in about 4 minutes. Slice the steaks if you like and serve the onions alongside.
Recipe found here.